Currently, we are reading the YAML resources from the manifests directory by the filenames which means users need to specify the same filenames the fleeting code expects. Instead of relying on the filenames, we should read all the YAML files from the manifests directory, validate the expected resources by the expected `kind`. Also, make sure only `kind:nmstateconfig` can be more than one and matches the total number of hosts ( `controlPlaneAgents` and `workerAgents` from AgentClusterInstall YAML). If the manifests resources have incorrect, missing, or different than the expected kind, guide the users accordingly.