Add helloOk field in isMaster op query

[chilagrow]

What should be done?

helloOk Protocol Negotation is used to check that the server and the client both supports the hello command. If the client sends helloOk: true in isMaster and server responds back with helloOk: true as well, then both parties can start sending hello instead of isMaster on the connection.

This allows appropriate response for the client which supports hello.

see also #4111 (comment)

Where?

https://github.com/FerretDB/FerretDB/blob/main/internal/handler/cmd_query.go

Definition of Done

• handler updated;
• integration/compatibility tests added/updated;
• spot refactorings done;
• user documentation updated or an issue to create documentation created;
• something else?