support default input source and fix layout

[JasprW]

No description provided.

[JasprW]

This MR contains:

1. supports setting default input source. Will change to default input source when application not matched in the condition list.
2. Fix layout for long app name and first launch padding issue.
   

[kaltar]

This should be pulled into the default! We have no option to download this via homebrew!

[awaescher]

This is a great addition, thanks a lot for implementing it. It works flawlessly.
I just made a new fork where I could fix two errors with the new Xcode and re-archived the executable.
I uploaded the binary on my fork in case someone wants to download the app.

• https://github.com/awaescher/SwitchKey