drpc: add a CLI flag to cockroach start command to enable DRPC #155592
Description
The switch from gRPC to DRPC is a fundamental low-level change that also affects the node's bootstrap process. For a node to successfully bootstrap, it needs to gossip with other nodes, an operation that requires making RPC calls.
The current approach of enabling or disabling DRPC through a cluster setting is not feasible because cluster settings themselves are propagated via RPC. This creates a circular dependency during bootstrap.
To resolve this, we plan to introduce a new CLI flag that allows enabling or disabling DRPC independently of cluster settings.
This ticket tracks the work to add a new CLI flag --use-new-rpc to cockroach start command to enable DRPC. DRPC is turned off by default.
Jira issue: CRDB-55500
Epic CRDB-55200