MessagePack extensions for the datetime and interval types

[veod32]

Related dev. issue(s): https://github.com/tarantool/tarantool/pull/6660/commits

Product: Tarantool
Since: 2.10.0
Root document: https://www.tarantool.io/en/doc/latest/dev_guide/internals/msgpack_extensions/
SME: @ igormunkin, @ tsafin

Details

• Describe new MessagePack extensions for the datetime type (similar to the description for UUID and decimal)
• Describe new MessagePack extensions for the interval type
• Link with the description of types here https://www.tarantool.io/en/doc/latest/book/box/data_model/#field-type-details
• Update .po files

Input from RnD:

• https://github.com/tarantool/tarantool/wiki/Datetime-Internals#messagepack-encoding-schema
• https://hackmd.io/@Mons/S1Vfc_axK#%D0%A3%D0%BF%D0%B0%D0%BA%D0%BE%D0%B2%D0%BA%D0%B0-%D0%B2-msgpack

Follow-up of #2509