Misc cleanup of type param handling code

[kevinbarabash]

• eagerly check type args satisfy constraints on type params and that we have the right number of type args
• eagerly check binary type operands
• dedupe expand_alias code

[codecov[bot]]

Codecov Report

Merging #671 (0043ffc) into main (323a948) will decrease coverage by 0.02%. The diff coverage is 90.32%.

@@            Coverage Diff             @@
##             main     #671      +/-   ##
==========================================
- Coverage   90.73%   90.71%   -0.02%     
==========================================
  Files         104      104              
  Lines       21956    21949       -7     
==========================================
- Hits        19922    19912      -10     
- Misses       2034     2037       +3     

Files Changed	Coverage Δ
crates/escalier_hm/src/unify.rs	84.09% <61.53%> (+0.10%)	:arrow_up:
crates/escalier_hm/src/util.rs	78.85% <92.30%> (-1.85%)	:arrow_down:
crates/escalier_hm/src/context.rs	100.00% <100.00%> (ø)
crates/escalier_hm/src/infer.rs	91.57% <100.00%> (+0.66%)	:arrow_up:

... and 5 files with indirect coverage changes