[Mobile] Allow automatic closing of panes when nav object is clicked

[rukmini-bose]

Closes #7313

Describe your changes:

• Adds vue logic such that when a mobile device is in portrait mode, clicking on navigation objects (from the tree, Recent Objects, or search) will automatically close the pane and navigate the user to the selected object
• Adds CSS logic such that the Object Tree is a static width. Currently, our code uses the desktop logic, causing the tree to change widths whenever we switch from desktop to mobile.

All Submissions:

• Have you followed the guidelines in our Contributing document?
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?
• Is this a notable change that will require a special callout in the release notes? For example, will this break compatibility with existing APIs or projects that consume these plugins?

Author Checklist

• Changes address original issue?
• Tests included and/or updated with changes?
• Has this been smoke tested?
• Have you associated this PR with a type: label? Note: this is not necessarily the same as the original issue.
• Have you associated a milestone with this PR? Note: leave blank if unsure.
• Is this a breaking change to be called out in the release notes?
• Testing instructions included in associated issue OR is this a dependency/testcase change?

Reviewer Checklist

• Changes appear to address issue?
• Reviewer has tested changes by following the provided instructions?
• Changes appear not to be breaking changes?
• Appropriate automated tests included?
• Code style and in-line documentation are appropriate?

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 56.17%. Comparing base (b2b0837) to head (340b4a6).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #7553      +/-   ##
==========================================
+ Coverage   56.14%   56.17%   +0.02%     
==========================================
  Files         672      672              
  Lines       27128    27133       +5     
  Branches     2635     2635              
==========================================
+ Hits        15232    15242      +10     
+ Misses      11569    11564       -5     
  Partials      327      327              

Flag	Coverage Δ
e2e-full	23.17% <100.00%> (-0.41%)	⬇️
e2e-stable	59.97% <80.00%> (+0.06%)	⬆️
unit	49.11% <80.00%> (+<0.01%)	⬆️

Files	Coverage Δ
src/ui/router/ApplicationRouter.js	88.23% <100.00%> (+0.60%)	⬆️

... and 4 files with indirect coverage changes

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[charlesh88]

Functionality looks great, good work. This PR is not intended to fix the tree vs. recent objects problem (#7357) which is going to create a problem when testing. So with that, some changes:

1. The original issue needs testing notes that include a callout about [Mobile Support] Object Tree is being hidden when switching from Portrait to Landscape Mode #7357. You should have the user exercise the system starting with tree collapsed and expanded, in both portrait and landscape, clicking from the tree and search results in all those permutations - except tree/landscape.
2. The PR checklist and author checklists need to be completed.

[rukmini-bose]

Testing Instructions: #7313

[charlesh88]

Looks great, thanks.