Protobuf support for Kafka sink connector

[mastannpu87]

Jira Link: DB-2105
Kafka sink connector support for protobuf payloads:

Proto file for the payload:

syntax = "proto3";
message Policy {
uint32 policyNumber = 1;
double policyPrice = 2;
string policyDetails = 3;
}

When using above payload user gets following error.

ERROR] 2021-07-16 21:06:55,852 [task-thread-YBSink-PB-1-0] org.apache.kafka.connect.runtime.WorkerSinkTask deliverMessages - WorkerSinkTask{id=YBSink-PB-1-0} Task threw an uncaught and unrecoverable exception. Task is being killed and will not recover until manually restarted. Error: Invalid schema for value STRUCT expected a map.
java.lang.IllegalArgumentException: Invalid schema for value STRUCT expected a map.

[tylarb]

Reference internal issue: 1760