Improve System Tag Feature

[rdymade]

Type: Feature
Priority: Mandatory for me to use it in production :)

Currently:
SystemTags currently are only supporting one letter from A-Z

Requirements:

• extend the system tag feature (and make them permanent) to a String of 20 Characters or maybe even more (mandatory)
• display the systemtag above the C[X] J...... and make it editable (mandatory)
• make it possible to add simple rules to autogenerate those systemtags (niceToHave)

@pfh59 this is something we currently implemented ourselfs for pathfinder and i would need the same for whmapper in order to go live with it for my alliance. If you don't want this feature in the main repo i would implement it just for my fork. i can understand if you don't want a feature like that.