use SelectableText in GUI for instance info

[levkropp]

closes #3821

This PR changes most Text widgets in the Instances and VM Details pages to SelectableText
SelectableText does not support overflow: ellipsis so I have set maxLines: 1 to ensure that table cells are still 1 line max.

I did not make the instance's name selectable in the Instances page because the name column has unique behavior implemented with VMNameLink where clicking it links to the instance's shell

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 89.02%. Comparing base (eeed24d) to head (0d04f37).
Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3852      +/-   ##
==========================================
- Coverage   89.02%   89.02%   -0.01%     
==========================================
  Files         255      255              
  Lines       14578    14577       -1     
==========================================
- Hits        12978    12977       -1     
  Misses       1600     1600              

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[andrei-toterman]

That's kind of a lengthy name IMO. You can name it just SelectableText and use import 'package:flutter/material.dart' hide SelectableText; so that you can use yours without interfering with Flutter's.
Also, you can move this to its own file. extensions.dart is more for defining useful extension methods on types rather than for widgets.

[levkropp]

You can name it just SelectableText and use import 'package:flutter/material.dart' hide SelectableText; so that you can use yours without interfering with Flutter's.

When I tried to do this I wasn't able to define the contextMenuBuilder parameter: The contextMenuBuilder parameter is not defined in the SelectableText widget.
So instead I moved the class into its own file at selectable_text.dart and renamed it to WhiteSelectableText

[andrei-toterman]

Yeah, it was because your SelectableText was conflicting with Flutter's here. You can circumvent this by importing Flutter under an alias in just this file. Take a look here where there is a custom Tooltip widget that wraps Flutter's Tooltip.

[andrei-toterman]

I understand if this feels weird, and maybe it creates confusion. But IMO it's better than coming up with more elaborate names for widgets just because Flutter used them first. I'm open to criticism though!