Test: Workspace extension recommendations

[chrmarti]

Test for #11936

• Any OS @dbaeumer

Complexity - 3

Configure

• Open Extensions view and click Extensions actions --> Configure Workspace Recommended extensions or Use Command pallette and find the action
• It opens extension.json file from .vscode folder. It creates one, if not there
• For an empty workspace, verify that an error is shown if this action is selected.
• Under recommendations section, add extensions. Format should be <publisher_id>.<extension_name>. You can also find it in the extension URL when you open it in the market place.
  Eg: felixfbecker.php-debug
• Test for the basic intellisense support in the file.

Show Recommendations

• After adding extensions to file, refresh the workspace
• Verify that a prompt is shown mentioning about workspace recommendations
• If recommended extensions are already installed, this prompt should not be shown
• Select Show Recommendations action to show the extensions in the viewlet
• Select Do not show again action to not show this message again for this workspace

Note: You can enable this prompt for the workspace by clearing the following key for the workspace from the local storage - extensionsAssistant/workspaceRecommendationsIgnore