DOCS-2199: Viam Python SDK correctness pass

[andf-viam]

First: This PR changes only code comments (that appear in Python SDK docs). No code was harmed in the making of this PR!

Fix straightforward correctness issues that are interfering with automated scraping, such as missing params or returns, formatting (mostly indents), etc. Common issues encountered; fixed:

• Params with multiline descriptions must indent wrapped lines, fixed.
• Returns with multiline descriptions must not indent wrapped lines, fixed.
• Converted multi-item returns to single-item returns: they are all really single-item anyways -- 1 tuple -- and the multi-approach resulted in inconsistencies between usage syntax (at function def) and parameters (in dedicated Parameters (Args:) section).
  • Other instances of tuple returns already do this (simple, explicit (but also has an unrelated indentation issue)), so this just brings non-conformers inline. Consistency required for automation.
• Added some missing returns (but please double check my work!)
• Corrected some incorrect return types (but please double check my work!)
• Added missing data type (str) to delete_fragment.
• Some quick typo fixes.
• Moved code examples to be above params for few cases where observed.

NOTES / FURTHER ACTION:
Observed the following further inconsistencies that I cannot fix:

• Motion service is missing a service.html page entirely (has: arm, mlmodel; 404: motion). Motion appears to be the only resource Viam-wide without one.
  • Perhaps relatedly, motion functions are all present in client.py file, also at odds with all other service resources, which use {servicename}.py for these method declarations.
• Almost all resources omit explicitly including timeout or extra in Params list (Args:), but Motion includes them explicitly. Should Motion remove these explicit (inherited?) entries?

Thanks Team! Happy to chat or answer any questions; hit me up. Apologies if I guessed wrong on any data types! As always, I greatly appreciate your time!

[github-actions]

Warning your change may break code samples. If your change modifies any of the following functions please contact @viamrobotics/fleet-management. Thanks!

component	function
base	is_moving
board	gpio_pin_by_name
camera	get_image
encoder	get_position
motor	is_moving
sensor	get_readings
servo	get_position
arm	get_end_position
gantry	get_lengths
gripper	is_moving
movement_sensor	get_linear_acceleration
input_controller	get_controls
audio	get_properties
pose_tracker	get_poses
power_sensor	get_power
motion	get_pose
vision	get_classifications_from_camera

[andf-viam]

Not sure if this works, is this how to escape newlines in code examples in autoapi? Alternatively, likely safe to remove the newline. As is it breaks formatting.

[stuqdog]

Almost all resources omit explicitly including timeout or extra in Params list (Args:), but Motion includes them explicitly. Should Motion remove these explicit (inherited?) entries?

Yes, I suspect that Motion should stop including extra and timeout in the docstring for consistency with the rest of the SDK. I'm not sure why it differs in this way; @njooma do you know?

Probably also we should have a motion.py that defines an abstract base class that the client inherits from, but that definitely seems outside of scope here.

[stuqdog]

lgtm!

[andf-viam]

@stuqdog thank so much! Mergin' in!