Add plugin representation protos used for the RPC service and data between language servers.
Add plugin representation protos used for the RPC service and data between language servers.

PiperOrigin-RevId: 454913844
Change-Id: I498f98cf5bd6ff5a6dafa8a088f5d465be99707b

google/tsunami-security-scanner,google/tsunami-security-scanner,google/tsunami-security-scanner