Remove redundant param_count field from CallFrame

[HalidOdat]

Hopefully this is will be a PR in a series of PRs to refactor the way we call functions and in general and making it easier to implement some optimizations, breaking it down into smaller parts for easier review :)

It changes the following:

• Remove redundant param_count field from CallFrame
• Make pc, fp,, etc a u32.

[github-actions]

Test262 conformance changes

Test result	main count	PR count	difference
Total	93,990	93,990	0
Passed	74,620	74,620	0
Ignored	17,622	17,622	0
Failed	1,748	1,748	0
Panics	0	0	0
Conformance	79.39%	79.39%	0.00%

[codecov]

Codecov Report

Merging #2962 (b2ec55c) into main (7ae8582) will decrease coverage by 0.01%.
The diff coverage is 64.93%.

@@            Coverage Diff             @@
##             main    #2962      +/-   ##
==========================================
- Coverage   50.02%   50.02%   -0.01%     
==========================================
  Files         446      446              
  Lines       45903    45896       -7     
==========================================
- Hits        22963    22959       -4     
+ Misses      22940    22937       -3     

Impacted Files	Coverage Δ
boa_engine/src/vm/opcode/control_flow/return.rs	72.72% <0.00%> (ø)
boa_engine/src/vm/opcode/environment/mod.rs	53.53% <0.00%> (ø)
boa_engine/src/vm/opcode/mod.rs	45.45% <ø> (ø)
boa_engine/src/vm/opcode/templates/mod.rs	95.83% <0.00%> (ø)
boa_engine/src/vm/opcode/generator/mod.rs	13.39% <7.69%> (ø)
boa_engine/src/vm/opcode/jump/mod.rs	71.42% <40.00%> (ø)
boa_engine/src/vm/opcode/control_flow/throw.rs	83.51% <57.14%> (ø)
boa_engine/src/vm/opcode/control_flow/finally.rs	74.35% <83.33%> (+2.56%)	⬆️
boa_engine/src/vm/mod.rs	53.89% <90.90%> (+0.27%)	⬆️
boa_engine/src/vm/call_frame/mod.rs	100.00% <100.00%> (+10.52%)	⬆️
... and 9 more

... and 1 file with indirect coverage changes

[nekevss]

Looks good to me!