feat: notation plugin install command

[Two-Hearts]

This PR is based on the new spec: #809

It supports following notation plugin installations:

1. Install from .tar.gz/.zip file in file system
2. Install from HTTPS URL, SHA256 checksum is required
3. Install a plugin executable file in file system

Test: Corresponding E2E test cases are added in this PR as well.

Note: This PR depends on the notation-go PR: notaryproject/notation-go#364

The notation-go PR: notaryproject/notation-go#364 has been Merged.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 59.56113% with 129 lines in your changes missing coverage. Please review.

Project coverage is 63.59%. Comparing base (df8596d) to head (45788ae).
Report is 114 commits behind head on main.

Files with missing lines	Patch %	Lines
cmd/notation/plugin/install.go	58.37%	78 Missing and 14 partials ⚠️
internal/osutil/file.go	47.91%	18 Missing and 7 partials ⚠️
cmd/notation/internal/plugin/plugin.go	57.14%	8 Missing and 4 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #827      +/-   ##
==========================================
- Coverage   64.39%   63.59%   -0.80%     
==========================================
  Files          42       45       +3     
  Lines        2390     2692     +302     
==========================================
+ Hits         1539     1712     +173     
- Misses        720      824     +104     
- Partials      131      156      +25     

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[shizhMSFT]

LGTM

[priteshbandi]

LGTM.

We should track all the open comments in an issue and address them before 1.1 release

[Two-Hearts]

@priteshbandi As discussed, issue created: #853