Add menubar icon for KeePassium for Mac

[bernarddavis]

It would be great to have a menubar icon for KeePassium for Mac to provide quick access to search for an item when you're not within Safari using autofill.

This is available in 1Password with "1Password Mini", and an option is available in BitWarden that opens/hides the main window when the menubar icon is clicked. Ideally activating KeePassium from the menubar icon would focus the search box automatically, or provide an option to do this.

I used 1Password Mini to quickly search for items when autofill didn't provide a great result, or when I wasn't using a browser extension, and this would be a great convenience feature in KeePassium for Mac.

[keepassium]

Thank you for the suggestion! Nice-to-haves for the Mac version will likely be pushed to distant future, but it is useful to have a list ready when the future comes :)