Improve handling of mixed case

[planetf1]

When the operator was originally developed, it was assumed the configmap names would exactly match the egeria server names.

However the former are restricted to be a valid DNS name - including being lowercase only - whilst the latter can be mixed case.

Currently the code mostly assumes they are the same until the filenames are needed, whereby it then introspects the configmap and restores the original case...

Need to look at

• clarifying how case is handled in the docs
• simplyfying the code - perhaps by keeping the server name & config name very distinct