fix(relay/client):error handling for rpc's and replacing errgroup with sync.WaitGroup

[Prateeknandle]

1. Refactors the connectToKubeArmor function to replace the usage of errgroup.Group with sync.WaitGroup for managing goroutines and introduces a mechanism to stop all goroutines if any one of them encounters an error.

2. Introduced a shared stop channel to signal all goroutines to stop if any one of them encounters an error.

3. Added a buffered errCh channel to propagate errors from the goroutines back to the connectToKubeArmor function.

4. Implemented error propagation within each watcher function. If a goroutine encounters an error, it sends the error to errCh and returns.

5. Updated connectToKubeArmor to listen for errors on errCh and to close the stop channel to signal all goroutines to stop if an error occurs.

6. Ensured that it waits for all goroutines to finish before proceeding with client destruction if no error is found.

Tested manually by scheduling an error. After the error hit, the other goroutines will end and new connection will be made with the rpc's. Also checked logs and alerts after error, they are working as expected.

Logs, shows reconnection happens:

{"level":"info","ts":"2024-05-21 19:14:42.122527","caller":"log/logger.go:54","msg":"Checked the liveness of KubeArmor's gRPC service (192.168.29.12:32767)"}
{"level":"info","ts":"2024-05-21 19:14:42.122699","caller":"log/logger.go:49","msg":"Started to watch messages from 192.168.29.12:32767"}
{"level":"info","ts":"2024-05-21 19:14:42.122813","caller":"log/logger.go:49","msg":"Started to watch alerts from 192.168.29.12:32767"}
{"level":"info","ts":"2024-05-21 19:14:42.122896","caller":"log/logger.go:49","msg":"Started to watch logs from 192.168.29.12:32767"}

{"level":"warn","ts":"2024-05-21 19:17:12.151194","caller":"log/logger.go:79","msg":"failed to receive a log (192.168.29.12:32767) rpc error: code = Unknown desc = Just dying after 150 seconds"}
// error in watchlogs
{"level":"info","ts":"2024-05-21 19:17:12.151546","caller":"log/logger.go:54","msg":"Destroyed the client (192.168.29.12:32767)"}
{"level":"info","ts":"2024-05-21 19:17:12.527710","caller":"log/logger.go:54","msg":"Checked the liveness of KubeArmor's gRPC service (192.168.29.12:32767)"}
{"level":"info","ts":"2024-05-21 19:17:12.527820","caller":"log/logger.go:49","msg":"Started to watch messages from 192.168.29.12:32767"}
{"level":"info","ts":"2024-05-21 19:17:12.527858","caller":"log/logger.go:49","msg":"Started to watch alerts from 192.168.29.12:32767"}
{"level":"info","ts":"2024-05-21 19:17:12.527886","caller":"log/logger.go:49","msg":"Started to watch logs from 192.168.29.12:32767"}