Reparent grabbed entity onto wrist object upon grab

[mrxz]

Description:
Proof-of-concept demonstrating the simplified logic for grabbing when reparenting.
The grabbed element is reparented to the wristObject upon grab, and inversely restored to its original parent upon release.

Unrelated to this change:

• grabbing is a bit finicky (see Duplicate pinch events on the Quest Pro #5505)
• hand-tracking-grab-controls is broken due to a Three.js update:

2c70bc24596dd644084e66b0010dab5b1ff208ef is the first bad commit
commit 2c70bc24596dd644084e66b0010dab5b1ff208ef
Author: Diego Marcos <[email protected]>
Date:   Thu Jul 25 18:25:35 2024 -0700

    Bump THREE to r167

 package.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

[mrxz]

@dmarcos Rebased and updated this PR so that it no longer stores a temp variable on the grabbed entity. No longer marking as a draft as I think it's worth fixing hand-tracking-grab-controls which is currently broken on master.

[dmarcos]

Thanks!