Easy way to copy Ticket# with a single click

[Stubenhocker]

@Stubenhocker

This could for example also make merging tickets inside of Zammad simpler by switching between tabs or linking them without having to read the recently viewed tickets again.

I’ve noticed it is actually not possible to merge a ticket by entering “Ticket# <number>”, it only works when entering the number by itself. Would be nice if this could be adjusted, but maybe there are some potential complications when changing this with custom Ticket hooks.