Transaction support for scripting

[PragmaTwice]

Search before asking

• I had searched in the issues and found no similar issues.

Motivation

• Pass context into scripting and use one context for all commands in one script
• Key locking improvement (Hoist key mutexes from every command impls to Connection::ExecuteCommand #2563)
• Remove global lock for EVAL command

Solution

--

Are you willing to submit a PR?

• I'm willing to submit a PR!

[PokIsemaine]

We might be able to use a script flag like no-atomic (or maybe the flag name isn't appropriate, we can discuss it further) to allow the user to choose to execute the script completely exclusively or allow the script using Context + Key Lock.

[PragmaTwice]

Ahhh since the lua runtime is not thread-safe, we should remove the global lua context (inside Server) and utilize the worker-local lua runtimes (inside every Worker) to execute lua functions.

AS IS:

global lua runtime: EVAL, FCALL

worker-local lua runtimes: EVAL_RO, FCALL_RO

TO BE:

worker-local lua runtimes: EVAL, EVAL_RO, FCALL, FCALL_RO