Move mocked input handling from KeyboardManagerTest projects to common

[arjunbalgovind]

Move the mocked input and low level keyboard logic introduced in #4004 to common, as the classes/interfaces can be re-used for testing any low level keyboard hook and or anything involving keyboard input.
This comment mentions all the files that can be re-used #4004 (comment)

[crutkas]

@arjunbalgovind how expensive of a fix is this?

[arjunbalgovind]

It should be straightforward and quick.