Purpose of the feature.
Add support for killSessions and killAllSessions commands, which are currently supported in MongoDB.

The killSessions command kills the sessions that are specified by the user (https://www.mongodb.com/docs/manual/reference/command/killSessions/), and the killAllSessions command kills all sessions for the user(s) (https://www.mongodb.com/docs/manual/reference/command/killAllSessions/).

Describe the solution you'd like
killSessions

• This seems to be defined as a valid command in the gateway:

  documentdb/pg_documentdb_gw/src/processor/constant.rs

  Line 467 in da17575

  command_name: "killSessions",

  
  but when connecting to mongosh and running the command, we get a CommandNotSupported error

[direct: mongos] test> db.runCommand( { killSessions: [ { id: UUID('c9351465-eece-4ae7-8d91-3d71e54cb3d2') } ] } )
MongoServerError[CommandNotSupported]: Unknown request received: killSessions

• Add/fix functionality for killSessions in the gateway

killAllSessions

• Add functionality for the killAllSessions command according to the MongoDB documentation in the gateway

Describe alternatives you've considered
N/A

Additional context
N/A