QADC Update: Background Subtraction, CFD Edge Detection

[slactjohnson]

Description

Adds the new PVs that have been recently added to the QADC IOC to the QADC python class. Also removes duplicate code for the qadc in the pcdsdevices codebase.

Motivation and Context

Helps support Jira ticket ECS-5843.

Closes #1190

How Has This Been Tested?

Tested interactively with a QADC running the new IOC in TMO.

Where Has This Been Documented?

This PR.

Screenshots:

Typhos screen of OUT0:

Control Screen:

Pre-merge checklist

• Code works interactively
• Code contains descriptive docstrings, including context and API
• New/changed functions and methods are covered in the test suite where possible
• Test suite passes locally
• Test suite passes on GitHub Actions
• Ran docs/pre-release-notes.sh and created a pre-release documentation page
• Pre-release docs include context, functional descriptions, and contributors as appropriate

[slactjohnson]

Waiting for the QADC PR to get reviewed, merged, and released prior to marking this ready for review.