Add description param to security group commands

[rbaker11]

Issue #, if available:
#6981

Description of changes:
This adds the ability to add a description when creating security group rules via a dedicated option (--description) instead of only via the --ip-permissions option.

I also added a unit test for the new functionality. Total code coverage for this file (awscli/customizations/ec2/secgroupsimplify.py) has improved from 89% to 92%.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[codecov-io]

Codecov Report

Merging #4434 into develop will increase coverage by 0.03%.
The diff coverage is 100%.

@@             Coverage Diff             @@
##           develop    #4434      +/-   ##
===========================================
+ Coverage     94.5%   94.53%   +0.03%     
===========================================
  Files          188      188              
  Lines        14168    14174       +6     
===========================================
+ Hits         13390    13400      +10     
+ Misses         778      774       -4

Impacted Files	Coverage Δ
awscli/customizations/ec2/secgroupsimplify.py	92.38% <100%> (+3.49%)	⬆️
awscli/testutils.py	66.1% <0%> (+0.18%)	⬆️

---

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[codecov-io]

Codecov Report

Merging #4434 into develop will increase coverage by 0.03%.
The diff coverage is 100%.

@@             Coverage Diff             @@
##           develop    #4434      +/-   ##
===========================================
+ Coverage     94.5%   94.53%   +0.03%     
===========================================
  Files          188      188              
  Lines        14168    14174       +6     
===========================================
+ Hits         13390    13400      +10     
+ Misses         778      774       -4

Impacted Files	Coverage Δ
awscli/customizations/ec2/secgroupsimplify.py	92.38% <100%> (+3.49%)	⬆️
awscli/testutils.py	66.1% <0%> (+0.18%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update cef5bd1...fcf17fa. Read the comment docs.

[codecov-io]

Codecov Report

Merging #4434 into develop will increase coverage by 0.03%.
The diff coverage is 100%.

@@             Coverage Diff             @@
##           develop    #4434      +/-   ##
===========================================
+ Coverage     94.5%   94.53%   +0.03%     
===========================================
  Files          188      188              
  Lines        14168    14174       +6     
===========================================
+ Hits         13390    13400      +10     
+ Misses         778      774       -4

Impacted Files	Coverage Δ
awscli/customizations/ec2/secgroupsimplify.py	92.38% <100%> (+3.49%)	⬆️
awscli/testutils.py	66.1% <0%> (+0.18%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update cef5bd1...fcf17fa. Read the comment docs.

[codecov-io]

Codecov Report

Merging #4434 into develop will increase coverage by 0.03%.
The diff coverage is 100%.

@@             Coverage Diff             @@
##           develop    #4434      +/-   ##
===========================================
+ Coverage     94.5%   94.53%   +0.03%     
===========================================
  Files          188      188              
  Lines        14168    14174       +6     
===========================================
+ Hits         13390    13400      +10     
+ Misses         778      774       -4

Impacted Files	Coverage Δ
awscli/customizations/ec2/secgroupsimplify.py	92.38% <100%> (+3.49%)	⬆️
awscli/testutils.py	66.1% <0%> (+0.18%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update cef5bd1...fcf17fa. Read the comment docs.

[codecov-io]

Codecov Report

Merging #4434 into develop will increase coverage by 0.03%.
The diff coverage is 100%.

@@             Coverage Diff             @@
##           develop    #4434      +/-   ##
===========================================
+ Coverage     94.5%   94.53%   +0.03%     
===========================================
  Files          188      188              
  Lines        14168    14174       +6     
===========================================
+ Hits         13390    13400      +10     
+ Misses         778      774       -4

Impacted Files	Coverage Δ
awscli/customizations/ec2/secgroupsimplify.py	92.38% <100%> (+3.49%)	⬆️
awscli/testutils.py	66.1% <0%> (+0.18%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update cef5bd1...fcf17fa. Read the comment docs.

[codecov-io]

Codecov Report

Merging #4434 into develop will increase coverage by 0.03%.
The diff coverage is 100%.

@@             Coverage Diff             @@
##           develop    #4434      +/-   ##
===========================================
+ Coverage     94.5%   94.53%   +0.03%     
===========================================
  Files          188      188              
  Lines        14168    14174       +6     
===========================================
+ Hits         13390    13400      +10     
+ Misses         778      774       -4

Impacted Files	Coverage Δ
awscli/customizations/ec2/secgroupsimplify.py	92.38% <100%> (+3.49%)	⬆️
awscli/testutils.py	66.1% <0%> (+0.18%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update cef5bd1...fcf17fa. Read the comment docs.

[justindho]

Hi @rbaker11, thanks for the PR. Apologies for the delay in getting back to you. Our team just put out a contribution guide detailing improvements to the contribution process. I have created issue #6981 for this PR. We will wait for the issue to receive 10 upvotes before moving this PR into the ready-for-review stage on our project board. The rationale for this can be found in the rationale section of the contribution guide.” Until then, I'm going to set this PR as a draft.

[tim-finnigan]

Checking in as there has not been any recent activity here or on the corresponding issue (#6981). I think some further discussion is required regarding the use cases for the parameter, and why using --ip-permissions is not sufficient to pass the description. I'm going to close this PR pending further discussion in the issue but it can be revisited in the future.