Feature: Fetch messages sorted by a criteria on the API

[hoh]

As a user of the API, I would like to have the result sorted using the API 's sort_by and sort_order arguments.

See the API implementation: https://github.com/aleph-im/pyaleph/blob/main/src/aleph/web/controllers/messages.py#L58-L68

[philogicae]

Solved by 2 PRs:

• PR 1 on SDK
• PR 2 on PyAleph