sidecar: Use zap as logger backend

[black-dragon74]

This patch sets zap as logger backend for klog
and controller runtime.

Setting the logger is required by controller runtime, not doing so leads to an error in the logs like:

[controller-runtime] log.SetLogger(...) was never called; logs will not be displayed.
Detected at:
        >  goroutine 26 [running]:
        >  runtime/debug.Stack()
        >       /usr/local/go/src/runtime/debug/stack.go:26 +0x5e
        >  sigs.k8s.io/controller-runtime/pkg/log.eventuallyFulfillRoot()
        ....

[Madhu-1]

Please update the PR description/commit message to show what exact error you are seeing now without this change.