☂️ Add support for Tarantool 3.0

[ylobankov]

• Add treegen.lua helper from tarantool to luatest and adapt it #364
• Add justrun.lua helper from tarantool to luatest and adapt it #365
• Add cbuilder.lua helper from tarantool to luatest and adapt it #366
• Support Tarantool 3.0+ stuff in server.lua #367
• Add cluster.lua module from tarantool to luatest and adapt it #368

[Totktonada]

All the subtasks are done.