Removes inconsistently applied and mostly no-op double click blocking.

[rtibbles]

Summary

Double click blocking was originally introduced to prevent a problem seen in user navigation through the topic tree, where users would double click, resulting in a double navigation. This click blocking is no longer applied on topic navigation (there is no click mask) and yet the issue does not still seem to be prevalent.

Cleans up the click blocking logic which appears to do nothing at this juncture.

References

See original implementing PR for reference: #3915
Also fixes #7444

Reviewer guidance

I am targeting this for Planned Patch 1, as it is useful cleanup, but doesn't need to block release, and could do with a little bit of QA to ensure it doesn't introduce a regression.

The only places that might be affected is when viewing a resource in Learn, and when moving between different pages during user login/signup.

Testing checklist

• Contributor has fully tested the PR manually
• If there are any front-end changes, before/after screenshots are included
• Critical user journeys are covered by Gherkin stories
• Critical and brittle code paths are covered by unit tests

PR process

• PR has the correct target branch and milestone
• PR has 'needs review' or 'work-in-progress' label
• If PR is ready for review, a reviewer has been added. (Don't use 'Assignees')
• If this is an important user-facing change, PR or related issue has a 'changelog' label
• If this includes an internal dependency change, a link to the diff is provided

Reviewer checklist

• Automated test coverage is satisfactory
• PR is fully functional
• PR has been tested for accessibility regressions
• External dependency files were updated if necessary (yarn and pip)
• Documentation is updated
• Contributor is in AUTHORS.md

[github-actions]

Build Artifacts

Asset type	Download link
PEX file	kolibri-0.16.0b10.dev0_git.114.gb901a4ed.pex
Windows Installer (EXE)	kolibri-0.16.0b10.dev0+git.114.gb901a4ed-unsigned.exe
Debian Package	kolibri_0.16.0b10.dev0+git.114.gb901a4ed-0ubuntu1_all.deb
Mac Installer (DMG)	kolibri-0.16.0b10.dev0+git.114.gb901a4ed-0.3.0.dmg
Android Package (APK)	kolibri-0.16.0b10.dev0+git.114.gb901a4ed-0.1.0-debug.apk
TAR file	kolibri-0.16.0b10.dev0+git.114.gb901a4ed.tar.gz
WHL file	kolibri-0.16.0b10.dev0+git.114.gb901a4ed-py2.py3-none-any.whl

[marcellamaki]

With some testing, I cannot seem to find anything with navigating the tree that is not working properly as a result of this. I think it is good to merge, and if for some reason anything pops up in later QA or regression testing, we can address it.