waveform: Implement scaling

[bkeryan]

• This contribution adheres to CONTRIBUTING.md.

What does this Pull Request accomplish?

Add scale mode types:

• ScaleMode: base class with a private _transform_data method
• NoneScaleMode: implementation that doesn't scale anything
• NO_SCALING: singleton instance of NoneScaleMode
• LinearScaleMode: implementation that scales linearly

Add AnalogWaveform members:

• scale_mode: get/set the scale mode
• get_raw_data: get a subset of the raw data
• get_scaled_data: get a subset of the scaled data and/or scale to float32

Add _utils.arg_to_float and rework arg_to_int slightly. The biggest change is that args are required by default and optional if you specify default_value.

Change "Provided value:" error messages to use repr.

Why should this Pull Request be merged?

Closes AB#3082118 - Add waveform scaling

What testing has been done?

Ran new unit tests

[github-actions]

Test Results

   10 files  ±  0     10 suites  ±0   19s ⏱️ ±0s
  268 tests + 63    263 ✅ + 63   5 💤 ±0  0 ❌ ±0 
2 680 runs  +630  2 630 ✅ +630  50 💤 ±0  0 ❌ ±0 

Results for commit 6993792. ± Comparison against base commit 55a6723.

♻️ This comment has been updated with latest results.