Add inputSource and inOutSource to Module

[mkorbel1]

Description & Motivation

Adds new APIs to Module to access the original "driver" or "source" when an input or inOut port was created.

See #501 for more information on motivation, etc.

Also, removed the @protected on various APIs related to accessing inputs and inOuts on Modules since (a) it wasn't really protecting much during hardware generation since modules could access it without lint warning, and (b) because the proper use and connectivity of the APIs is already dependent on user understanding of in/out rules for module building.
 

Related Issue(s)

Fix #501

Testing

Add tests for new APIs + existing tests to make sure nothing broke

Backwards-compatibility

Is this a breaking change that will not be backwards-compatible? If yes, how so?

Variable name changes from x to source on port creation APIs may trigger warnings on overrides of those functions, but not breaking.

Documentation

Does the change require any updates to documentation? If so, where? Are they included?

No