Client integration with server apps issues

[camilasan]

Remaining issues with client integration (#9403):

• close window once user clicks on link to open sync folder in the browser
• check parsing of elements returned by the app in the response after action has been triggered, e.g. URL fix: Robustly parse file action responses and handle tooltip/URL children #9547
• check dark/light mode of icons
• increase size of close button icon
• sometimes it throws the error that the file ID is empty (also see workaround in tests test(integration): add tests for FileActionsModel. #9518)