Use consistent naming for initialisms in cmd
requested to merge gitlab-community/cluster-integration/gitlab-agent:fix-remaining-initialisms-in-cmd-1 into master
This MR includes mostly changes in the agentkapp and kas packages. During the refactoring also a couple of changes have been done in internal. This MR does not include all the renamings but only the following:
- Rename agentRpcApi to agentRPCAPI
- Rename TryGetAgentId to TryGetAgentID
- Rename GetGitLabExternalUrl to GetGitLabExternalURL
- Rename GetAgentId to GetAgentID
- Rename gitLabExternalUrl to gitLabExternalURL
- Rename setupApi to setupAPI
- Rename setupApiWithStream to setupAPIWithStream
- Rename agentId to agentID