Update messages.en.yaml

[TheVillageGuy]

Shorten subscribe/unsubscribe to prevent buttons forming two rows

[melroy89]

Also we might still want to show the full line "Subscribe" and "Unsubscribe" to the users when they mouse-over the button, using the HTML title tag. Hence it might be better to create a new translation strings for the abbreviations.

[BentiGorlich]

@TheVillageGuy some tests do use text to recognize some buttons so when you change it it will not find those buttons anymore and then you'll get errors like "current node list is empty".
When you go to the failed pipeline you will get the test errors with the files they originate from. Then you can fix them

[TheVillageGuy]

Also we might still want to show the full line "Subscribe" and "Unsubscribe" to the users when they mouse-over the button, using the HTML title tag. Hence it might be better to create a new translation strings for the abbreviations.

Good point, I'll add them soon.

@BentiGorlich I'm going to have to figure out how those tests work then, that's going to take some time