Plan: Rename caosdb-cpplib to linkahead-cpplib

Plan:

• what needs to be changed? -> see #87 (comment 79782)
• what parts will be more complicated than string replacement? -> proto repo
• How backwards-compatible do we want to remain?
  • config files -> support both caosdb_client.json and linkahead_client.json, with deprecation warning for the former
  • Julialib/octavelib (#87 (comment 79820))