Gmoshkin/config.yaml more box cfg parameters

Summary

• feat: config.yaml move instance.log* -> instance.log.*

• feat: config.yaml miscellaneous parameters

• feat: config.yaml instance.iproto section

• feat: config.yaml instance.vinyl section

• feat: config.yaml instance.memtx section

• feat: Introspection::get_field_as_rmpv

• refactor: tarantool::Cfg::other_fields catchall

• refactor: tarantool::cfg().is_some() -> tarantool::is_box_configured()

• Close #...
• Changes should be cherry-picked to 24.2: no
• Docs follow-up: docs#200 (closed)