Feature/146 groups case sensitivity

[dk1844]

Originally with /token/generate?group-prefixes=prefix1,PREFIX2,PREFiX3, the prefixes were always case-sensitive. This proved to be less than ideal.

Newly, there is a optional param case-sensitive=true|false (default: false if not given) that governs how group prefixes filtering is done.

Release notes:

• Previously existing /token/generate?group-prefixes=prefixHere is no longer case-sensitive by default. One may add &case-sensitive=true to bring back previous behavior.

Closes #146

Migration notes:

Login service v1.6.0 and older's /token/generate?group-prefixes=prefixesHere equivalent will now be /token/generate?group-prefixes=prefixesHere&case-sensitive=true

[github-actions]

Report: Report: api - scala:2.12.17

Metric (instruction)	Coverage	Threshold	Status
Overall	68.77%	43.0%	✅
Changed Files	90.71%	70.0%	✅

File Path	Coverage	Threshold	Status
TokenController.scala	81.42%	0.0%	✅
User.scala	100.0%	0.0%	✅

[jakipatryk]

Looks good overall, just these "`case-sensitive`" backquote-based arguments name looks weird and I personally prefer to not use them unless a Java library is used which forces us to have them, for example to adhere to an interface.