Refactor stream_readers and stream_writers into smaller files

[mikeprosserni]

• This contribution adheres to CONTRIBUTING.md.
• I've updated CHANGELOG.md if applicable.
• I've added tests applicable for this pull request

What does this Pull Request accomplish?

stream_readers.py and stream_writers.py were very large files, which made development and review more difficult. This PR splits the classes in them out into individual files to make things more manageable.

I was careful to keep each class unchanged through this refactor. I copy-pasted each entire class and made no edits within the classes. The only changes would be in the imports sections.

Why should this Pull Request be merged?

This should make reviewing future changes easier.

What testing has been done?

• All existing tests pass
• lint and mypy report no errors
• I checked the generated sphinx documentation for any changes. The files are largely unchanged, with only a few minor modifications:
  • An extra top level blurb: "NI-DAQmx stream writers. This package provides classes for writing samples to NI-DAQmx tasks."
  • Source code links changed from (for example) stream_writers.html to stream_writers/analog_multi_channel_writer.html
  • <nidaqmx.stream_writers.UnsetAutoStartSentinel object> changed to <nidaqmx.stream_writers._channel_writer_base.UnsetAutoStartSentinel object>

[github-actions]

Test Results

    38 files  ±0      38 suites  ±0   1h 1m 55s ⏱️ +21s
 2 675 tests ±0   2 232 ✅ ±0    443 💤 ±0  0 ❌ ±0 
47 382 runs  ±0  40 226 ✅ ±0  7 156 💤 ±0  0 ❌ ±0 

Results for commit 00f4176. ± Comparison against base commit 859c18d.

♻️ This comment has been updated with latest results.

[zhindes]

Just snooping, but... love this. Thank you!

[mikeprosserni]

Here's the doc diffs on readthedocs:

https://nidaqmx-python--816.org.readthedocs.build/en/816/stream_readers.html?readthedocs-diff=true&readthedocs-diff-chunk=1

https://nidaqmx-python--816.org.readthedocs.build/en/816/stream_writers.html?readthedocs-diff=true&readthedocs-diff-chunk=1

[bkeryan]

<nidaqmx.stream_writers.UnsetAutoStartSentinel object> changed to <nidaqmx.stream_writers._channel_writer_base.UnsetAutoStartSentinel object>

This sounds like compatibility breakage. Previously, clients could import UnsetAutoStartSentinel and AUTO_START_UNSET, and now they can't.

[mikeprosserni]

I'm fixing this in #825

[mikeprosserni]

Note that UnsetAutoStartSentinel is deleted right after being declared, so users could never import it, they could only import AUTO_START_UNSET itself.

class UnsetAutoStartSentinel:
    pass


AUTO_START_UNSET = UnsetAutoStartSentinel()

del UnsetAutoStartSentinel

[bkeryan]

This PR introduces public submodules, which introduces another way for clients to import these classes. Shouldn't the new submodules be private?

Most of the pain this causes is related to documentation, but it sounds like autodoc is handling this better than autoapi would.

[bkeryan]

We used private submodules for task, etc.

[mikeprosserni]

I'm fixing this in #825