Use consistent naming for remaining initialisms in modagent module
requested to merge gitlab-community/cluster-integration/gitlab-agent:fix-initialisms-modagent-module-2 into master
Improve naming for initialisms (#468 (closed)) in modagent module. This MR is a follow-up of !1248 (merged) and includes the following changes:
- Rename sourceId to sourceID in modagent module
- Rename TestErrorsOnDuplicateSourceId to TestErrorsOnDuplicateSourceID in modagent module
- Use consistent naming for initialisms for functions with RpcApi
- Rename rpcApi to rpcAPI in modagent module
- Rename rpcApiKey to rpcAPIKey in modagent module
- Rename RpcApiFactory to RPCapiFactory in modagent module