Add describe, delete, and list namespaces (REST)

[rohanshah18]

Problem

Add support for describe, delete, and and list namespaces for index and async index classes.

Solution

Following methods were added to the index and async index classes:

1. describe_namespace(self, namespace: str, **kwargs) -> "NamespaceDescription"
2. delete_namespace(self, namespace: str, **kwargs) -> Dict[str, Any]
3. list_namespaces:
   - list_namespaces(self, **kwargs) -> Iterator[ListNamespacesResponse] (for index.py)
   - list_namespaces(self, **kwargs) -> AsyncIterator[ListNamespacesResponse] (for index_asyncio.py)
4. list_namespaces_paginated(
   self, limit: Optional[int] = None, pagination_token: Optional[str] = None, **kwargs
   ) -> ListNamespacesResponse

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update
• Infrastructure change (CI configs, etc)
• Non-code change (docs, etc)
• None of the above: (explain here)

Test Plan

Added integration tests for both index and async index classes

[austin-denoble]

LGTM overall, left some comments and a few questions. Nice work, I'll defer to @jhamon for now on a lot of this as I'm still getting familiar with the client refactor.

[jhamon]

A couple things:

Require kwargs for new methods

I would add the @require_kwargs decorator on all new methods. Search the repo for other examples of this. We haven't added it in 100% of places because it would be a breaking change to add it to methods that never had it before if people are successfully calling methods using positional arguments, but we want to use this on all new methods going forward.

Why? Well, python is flexible in how methods are called. If you had a function like this:

def mymethod(foo):
  print(foo)

then you could call the function with positional arguments like mymethod('bar') or kwarg-style as mymethod(foo='bar'). Relying on positional arguments can cause problems down the road when new arguments are added, the args list gets long, if arguments transition from required to optional, etc. If everyone uses the keyword form from the beginning, a lot of these changes can be made without disrupting existing code.

Testing docs change

Unfortunately testing these docs changes is slightly involved because there's a problem preventing us from directly having sphinx as a dev-dependency. If you want to try building the docs, you need to follow the steps in this github action but do not commit any changes to the python version or poetry.lock when you are done.

Basically, you need to

• poetry env use 3.11 to make sure you're using python 3.11
• (Temporarily, do not commit) edit the pyproject.toml to require python ^3.11
• poetry install -E asyncio -E grpc
• Install docs deps poetry add sphinx myst-parser --group dev
• Build the docs poetry run sphinx-build -b html docs docsbuild
• Inspect the output open docsbuild/index.html

You will need to edit docs/rest.rst and docs/asyncio.rst to explicitly expose docs for your new methods, and then you'll want to look at them to see whether the generated text looks correct from a formatting standpoint.

[jhamon]

I left a ton of comments (sorry lol), but overall I think you did a nice job.