[rcore][web] Support mouse position update on HideCursor()

[Moros1138]

Fixes Issue #4940

The problem is relatively simple, CORE.Input.Mouse.cursorHidden was being used for both hiding the cursor and locking the cursor. This PR adds a variable to track when the cursor is locked so that the 2 states can be tracked independently of eachother.

[raysan5]

@Moros1138 My concern with this change is if it will change examples behaviour between platforms... if that's the case it should be addressed on all platforms.

[Moros1138]

Sorry for the after-editing, I compared the behavior with windows and made further changes to make the way web handles it closer to how it works on windows.. Here's a video

demo-mouse-hide-lock.mp4

[Moros1138]

@Moros1138 My concern with this change is if it will change examples behaviour between platforms... if that's the case it should be addressed on all platforms.

@raysan5 I was seeking to make the web platform work more as it does on windows. See video in previous post.

[Moros1138]

Is there a blocker for this PR that I have missed?

[raysan5]

@Moros1138 Just tested it and it breaks DisableCursor() behaviour, you can test core_3d_camera_first_person.

Please, be careful testing those PRs, there are many platforms and use cases involved and one solution for one of those could break other things.

[raysan5]

Just reviewed required code to add a new state.