Merge pull request #2908 from dart-lang/umop-testing-ui-dialogs

Testing closing of several dialogs
First implementation of search in files
nits
fixed checkmark
Disabled minimizeStack test
Merge pull request #2922 from dinhviethoa/disable-minimize-test

Disabled minimizeStack test
ignore case. progress fix.
Analyzer fixes
Added content placeholder when there's no results and when the search hasn't been started yet
Addresses comments
Merge pull request #2921 from dinhviethoa/859-search-in-files

First implementation of search in files
Changed project description (fixed #2849)
Merge pull request #2929 from dinhviethoa/2849-project-description

Changed project description
Attempt to solve Bug #2795. I've added a button in the UI and implemented added the backend function that changes the rootDirectory
suggested modification implemented but still without the redundancy on _showRootDirectory
Search fixes
Additional fixes
Search under a flag
Add commas
fix the bots