Support TCP keep alive in exporting process

[zyiou]

Is your feature request related to a problem? Please describe.
Exporting process keeps a connection to collector field for sending records. We currently maintain a goroutine to check connectivity of this connection by calling checkConnToCollector for a default interval (10s).

Describe the solution you'd like
We can replace checkConnToCollector by setting TCP keep alive for the connection. https://pkg.go.dev/net#TCPConn.SetKeepAlive
It will involve some refactoring of exporting process struct. Either add some customize wrapping/casting of TCPConn or keep two connection struct for udp and tcp protocols.

Describe alternatives you've considered
N/A

Additional context
N/A