Type safe root shape

[HalidOdat]

Currently when we construct a Realm we take a SharedShape as the root, since users can create realms to ensure that the passed shape is the root shape (otherwise if a non-root shape is passed, will at best cause a panic and at worse will give unexpected behaviour), added the RootShape that ensures that only a root shape is passed, this is applied to many other places where a root shape is required.

It changes the following:

• Add RootShape wrapper around SharedShape
• Implement From<UniqueShape> for Shape
• Implement From<SharedShape> for Shape

[github-actions]

Test262 conformance changes

Test result	main count	PR count	difference
Total	93,982	93,982	0
Passed	73,783	73,783	0
Ignored	17,489	17,489	0
Failed	2,710	2,710	0
Panics	0	0	0
Conformance	78.51%	78.51%	0.00%

[codecov]

Codecov Report

Merging #2940 (c3c68d1) into main (4a368a2) will increase coverage by 0.00%.
The diff coverage is 73.46%.

@@           Coverage Diff           @@
##             main    #2940   +/-   ##
=======================================
  Coverage   50.39%   50.39%           
=======================================
  Files         443      444    +1     
  Lines       45337    45349   +12     
=======================================
+ Hits        22846    22854    +8     
- Misses      22491    22495    +4     

Impacted Files	Coverage Δ
boa_engine/src/builtins/weak_map/mod.rs	14.11% <0.00%> (-0.35%)	⬇️
boa_engine/src/builtins/weak_set/mod.rs	13.75% <0.00%> (-0.36%)	⬇️
boa_engine/src/object/jsobject.rs	58.64% <ø> (ø)
boa_engine/src/object/shape/unique_shape.rs	26.80% <0.00%> (ø)
boa_engine/src/object/shape/mod.rs	80.95% <68.75%> (ø)
boa_engine/src/builtins/weak/weak_ref.rs	73.80% <100.00%> (+1.30%)	⬆️
boa_engine/src/context/intrinsics.rs	97.54% <100.00%> (+<0.01%)	⬆️
boa_engine/src/context/mod.rs	61.80% <100.00%> (ø)
boa_engine/src/object/property_map.rs	70.15% <100.00%> (+0.11%)	⬆️
boa_engine/src/object/shape/root_shape.rs	100.00% <100.00%> (ø)
... and 3 more

[raskad]

Looks very reasonable to me.

[jedel1043]

Nice improvement!