Havok Heightmaps

[carolhmj]

This PR adds support for the Heightfield shape in Havok. This shape requires that an array of heights is provided. This array can be optionally passed in the CreateGroundFromHeightMap callback, allowing for easy creation.

Example PG in: #I37D8G#15

[bjsplat]

Please make sure to label your PR with "bug", "new feature" or "breaking change" label(s).
To prevent this PR from going to the changelog marked it with the "skip changelog" label.

[bjsplat]

Snapshot stored with reference name:
refs/pull/14752/merge

Test environment:
https://babylonsnapshots.z22.web.core.windows.net/refs/pull/14752/merge/index.html

To test a playground add it to the URL, for example:

https://babylonsnapshots.z22.web.core.windows.net/refs/pull/14752/merge/index.html#WGZLGJ#4600

Links to test babylon tools with this snapshot:

https://playground.babylonjs.com/?snapshot=refs/pull/14752/merge
https://sandbox.babylonjs.com/?snapshot=refs/pull/14752/merge
https://gui.babylonjs.com/?snapshot=refs/pull/14752/merge
https://nme.babylonjs.com/?snapshot=refs/pull/14752/merge

To test the snapshot in the playground with a playground ID add it after the snapshot query string:

https://playground.babylonjs.com/?snapshot=refs/pull/14752/merge#BCU1XR#0

[bjsplat]

Experimental playwright test reporter:

https://babylonsnapshots.z22.web.core.windows.net/refs/pull/14752/merge/testResults/webgl2playwright/index.html

[RaananW]

Just making sure - it behaves like this:

https://playground.babylonjs.com/?snapshot=refs/pull/14752/merge#I37D8G#15