Fix comment placeholder text color, fixes https://github.com/Microsoft/vscode-pull-request-github/issues/63

* hacky fix #52522

* adding issue to comments

* addressing feedback

remove hover theming for menus as it no longer applies
remove unnecessary and conflicting high contrast theme border
use border over outline like hc

#37767

fixes #54420

* Seed random shuffle of extension recommendations

* Documentation

* ref #54092

* addressing feedback

fixes #54384