fix(adapter): fix elk client panic issue due to uninitialized waitgroup, ctx

[rksharma95]

{"level":"info","ts":"2024-12-16 15:17:16.180767","caller":"log/logger.go:54","msg":"Created a relay server (:32767)"}
{"level":"info","ts":"2024-12-16 15:17:16.180927","caller":"log/logger.go:49","msg":"Started to serve gRPC-based log feeds"}
{"level":"info","ts":"2024-12-16 15:17:16.180945","caller":"log/logger.go:49","msg":"Started to receive log feeds from each node"}
{"level":"info","ts":"2024-12-16 15:17:16.182049","caller":"log/logger.go:49","msg":"Initialized the Kubernetes client"}
{"level":"info","ts":"2024-12-16 15:17:16.185508","caller":"log/logger.go:54","msg":"Added a new client (f12f3795-2e9f-4181-bf6a-2c5d26093aa6, policy) for WatchAlerts"}
{"level":"info","ts":"2024-12-16 15:17:16.185648","caller":"log/logger.go:54","msg":"Added a new client (b70fb7af-10a7-488f-bf63-eca88e583699, system) for WatchLogs"}
{"level":"info","ts":"2024-12-16 15:17:16.186195","caller":"log/logger.go:54","msg":"Checked the liveness of the gRPC server"}
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x18 pc=0x1a287fc]

goroutine 63 [running]:
golang.org/x/sync/errgroup.(*Group).Go(0x0, 0xc000652030)
        /go/pkg/mod/golang.org/x/[email protected]/errgroup/errgroup.go:70 +0x1c
github.com/kubearmor/kubearmor-relay-server/relay-server/elasticsearch.(*ElasticsearchClient).Start(0xc000506740)
        /usr/src/kubearmor-relay-server/relay-server/elasticsearch/adapter.go:126 +0x13f
created by main.main in goroutine 1
        /usr/src/kubearmor-relay-server/relay-server/main.go:91 +0x388

[daemon1024]

Can we check other parts of the code? what's the below for loop for? how are client disconnects handled.