[Samples] Misc camera controller fixes

[Eideren]

PR Details

Fix BasicCameraController's mouse input, implements gamepad support, explain in detail common pitfalls of camera controller programming and fixes single frame lag on FPS sample's PlayerInput.

Description

Redondant.

Related Issue

None logged on Github.

Motivation and Context

This mostly stemmed from this Discord discussion I had a couple of weeks ago, creating this PR to fix the issue mentioned lower and clarify controller programming. This camera might very well be the first camera that users interact with, knowing that we might as well document thoroughly how it works and what users should do when modifying or creating one.

Types of changes

• Docs change / refactoring / dependency upgrade
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My change requires a change to the documentation.
• I have added tests to cover my changes.
• All new and existing tests passed.

Notes

• There still is at least one frame of lag somewhere else inside the engine, it is fairly visible when binding mouse input to a camera and looking at the OS cursor moving a fair amount of time before the in game camera does.
• I thought about modifying the first person camera to clarify it as well but that one's such a mess that I might as well rewrite it altogether.

[Eideren]

Changed to WIP: working on fixing the editor camera.

[Eideren]

PR ready for review

[xen2]

Thanks! Tested in editor/new game, it seems to be much better than before.

[xen2]

Merging, thanks for the great work and well commented code!

[xen2]

Note: will cherry-pick this if we release a 3.0.0.8

[xen2]

@Eideren
Except FPS sample, do you know if other samples will need a camera system rewrite?
(No need to fix this right away, it's more to create proper issues)

[Eideren]

@xen2 Well, the third person camera and orbit as well, so all of them sadly.

• Orbit is fairly straightforward so at least users shouldn't have too much trouble modifying it but the operations it does considers frame rate to stay at a constant 60 while decelerating the camera.
• Third person is the same as first, doesn't filter between offset and direction based inputs, uses fixed delta time instead of frame outside of physics loop and doesn't use delta time when necessary.
  Do you want me to create an issue about those ?

[xen2]

@Eideren sure, feel free to create a new issue if you don't mind, thanks.