Fast waveform upload on Keysight awg819x

[timoML]

Using the IVI-COM driver from Keysight, waveform upload speeds can be massively boosted (>200 MB/s via PCIe).

Description

Caveats:

• due to comtypes usage, only works on Windows
• the limiting factor in total upload time seems now often the binary sample compilation needed after getting floats from the sequence generator

How Has This Been Tested?

• 3 setups with both awg8190, 95.

Types of changes

• Bug fix
• New feature
• Breaking change (Causes existing functionality to not work as expected)

Checklist:

• My code follows the code style of this project.
• I have documented my changes in /docs/changelog.md.
• My change requires additional/updated documentation.
• I have updated the documentation accordingly.
• I have added/updated the config example for any module docstrings as necessary.
• I have checked that the change does not contain obvious errors
  (syntax, indentation, mutable default values, etc.).
• I have tested my changes using 'Load all modules' on the default dummy configuration.
• All changed Jupyter notebooks have been stripped of their output cells.

[timoML]

Please note that there is a confirmed memory leak occuring somewhere between the Keysight driver and comtypes (1.2.0). Uploading multiple waves will cause memory usage rise without proper clearing. Thanks @PJVetter for investigating.