Adopt vmihailenco/msgpack v5

[Totktonada]

Users want new msgpack v5 features and we should find a way to offer them.

First of all investigate and summarize all differences.

I imagine different ways to adopt it:

1. Configure v5 to work exactly like v2 by default. If it is not possible now, consider implementing the configuration options in the msgpack library and propose to authors. If it is really hard or will be declined, okay, not a way.
2. Support both v2 and v5 and allow a user to choose. For example in the same way as we do with uuid support: import tarantool/msgpack-v5 will pull v5 into dependencies and will enable it instead of v2.
3. Think. Think. Think. Define a set of non-breaking changes we want to offer before go-tarantool v2. Define a set of breaking features for the first go-tarantool v2 release (the discussion about go-tarantool v2 features is in V2 proposals #65).

There is a PoC: #97.