Convert control types constants into enums

[feerrenrut]

This issue stemmed from a comment in #10703

As a follow up, do the same for the rest of the constants in control types, and ensure that all of NVDA uses the enum versions and officially deprecate (and give a date of removal for) the module level constants.

While doing this, add a deprecation comment to SpeechReason constants also.

Originally posted by @feerrenrut in #10703

[LeonarddeR]

I think there are two implementation strategies:

1. Define the enums and after that, do a setattr on the module to add the old constants
2. Define a getattr at the module level that looks up the constants from the enums.

Performance wise, I'd do the former, but if you want to raise deprecation warnings, the latter is probably more effective.

Have you also considered constants in oleacc.py? I'd leave them as is.

[LeonarddeR]

An additional thought... May be we should advertise de labels using the enum itself?

class Role(enum.IntEnum):
	UNKNOWN = 0
	@property
	def label(self):
		return controlTypes.roleLabels[self]

[feerrenrut]

Pushing this back to 2020.3

[feerrenrut]

Given the possibility for breaking compatibility, I'm pushing this back to 2021.1

[feerrenrut]

Rather than do this all in one go, instead, similar to "Use enum for speech reason #10703" first we'll do this in a backwards compatible way so that add-on authors have a transitionary period. Later, probably 2022.1 we'll remove the deprecated aspects.

[seanbudd]

@feerrenrut - would the backwards compatible work be part of deprecations/2021.1 or should I start on this separately?

[feerrenrut]

@seanbudd the deprecation warnings don't necessarily need to be in this release. I think we should label this for 2022.1. The initial work to deprecate and provide a new alternative can be done after we get to beta for 2021.1.