CCLI: Implement improvements

[lkleisa]

In Ticket 720 we made a new concept for the Cryptopus CLI. Implement now one of the suggestion

TODO

• Decide for one suggestion
• Add this suggestion to this ticket description
• Implement suggestion
• Test it

[njaeggi]

Modal wurde implementiert, CCLI Custom Attrs PR ist fertig, was noch fehlt sind Tests bei #737

[kcinay055679]

Due to very limited usage of the CCLI, we have decided not to maintain it any further.