docs: Remove duplicate type hints in docstrings and annotations

[MortGron]

Description

The duplication of type hints in both docstring and as annotations makes the docstrings unnecessarily hard to read as a developer. It is possible to remove type hints in the docstrings without changing the structure of the documentation. This PR removes all type hints from the docstrings, but enables a Sphinx extension to keep the type hints in the documentation.

Current documentation:

New documentation:

A few points to discuss:

• Should it still be allowed to provide type hints in the docstrings? It might make sense for very long type hints to have a custom type hint instead
• Is the change in documentation look accepptable? All type hints are now stylized as inline code in the documentation, which in my opinion is slightly less readable than how it was.

Checklist:

• Tests added/updated.
• Documentation updated. Documentation is generated from docstrings - these must be updated according to your change.
  If a new method has been added it should be referenced in cognite.rst in order to generate docs based on its docstring.
• The PR title follows the Conventional Commit spec.