[3pt] introduce fiber_object:info() and fiber_object:csw()

[TarantoolBot]

New fiber_object:info() and fiber_object:csw() functions

Product: Tarantool
Since: 2.9.0-43-g9da7e03e8
Audience/target: Tarantool users
Root document: https://www.tarantool.io/en/doc/latest/reference/reference_lua/fiber/#lua-object.fiber.fiber_object
SME: @ Korablev77

Details

• fiber_object:info() is the same as fiber.info(), but show information only
  about one alive fiber.
• fiber_object:csw() show csw (Context SWitch) of alive fiber.

• Related development issues and/or commits: tarantool/tarantool@9da7e03

Definition of done

• New fiber_object:info() and fiber_object:csw() functions are desribed.

[patiencedaur]

Related: #2899

[olegrok]

Also don't forget to add note that fiber_obj:info() could accept options argument.
tarantool/tarantool#7211

In fact it's the same as for #2899