Add support for pagination

[jacobtomlinson]

This PR makes use of pagination when listing resources. This is expecially useful when working with clusters with large numbers of resources.

Breaking Changes

As a consequence the kr8s.get() and APIObject.list() methods have been changed to generators instead of returning lists. This allows us to iterate over all the resources in a Kubernetes cluster without using large amounts of memory.

This improves the API and makes it more Pythonic, but this is a breaking change for existing users.

Sync

In the sync API the kr8s.get() (and kr8s.api().get()) methods now return a generator instead of a list. This will break some indexing operations and require you to cast to a list to achieve the same functionality.

import kr8s

# Before
second_node = kr8s.get("nodes")[1]

# After
second_node = list(kr8s.get("nodes"))[1]

This also applies to methods that call this such as Nodes.list() or any other APIObject.list() method.

Async

In the async API the same applies and the kr8s.asyncio.get() method returns an async generator. To covert this to a list we need to asynchronously iterate over it.

import kr8s

# Before
nodes = await kr8s.asyncio.get("nodes")

# After
nodes = [node async for node in kr8s.get("nodes")]

This also changes the for functionality when looping over the method directly.

import kr8s

# Before
for node in await kr8s.get("nodes"):
    print(node.name)

# After
async for node in kr8s.get("nodes"):
    print(node.name)

Closes #477

[codecov]

Codecov Report

Attention: Patch coverage is 97.64706% with 2 lines in your changes missing coverage. Please review.

Project coverage is 95.12%. Comparing base (87063fc) to head (f874f10).
Report is 140 commits behind head on main.

Files with missing lines	Patch %	Lines
kr8s/_api.py	88.88%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #523      +/-   ##
==========================================
+ Coverage   94.61%   95.12%   +0.50%     
==========================================
  Files          29       30       +1     
  Lines        3141     4019     +878     
==========================================
+ Hits         2972     3823     +851     
- Misses        169      196      +27     

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