fix: delegate default impls in HugrView

[lmondada]

Without delegating all methods with default impls, you get the following weirdness that drove me crazy this morning

trait TraitFoo {
  fn something(&self) -> usize {
    return 42;
  }
}

impl<'t, T: TraitFoo> &'t T {}

struct A;

impl TraitFoo for A {
  fn something(&self) -> usize {
    return 0;
  }
}

let a = A();
a.something()     // is 0
(&a).something()  // is 42 :(

[codecov]

Codecov Report

Attention: Patch coverage is 47.82609% with 24 lines in your changes missing coverage. Please review.

Project coverage is 83.72%. Comparing base (2f588cb) to head (d45786c).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
hugr-core/src/hugr/views/impls.rs	47.82%	24 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1921      +/-   ##
==========================================
- Coverage   83.78%   83.72%   -0.07%     
==========================================
  Files         196      196              
  Lines       37493    37539      +46     
  Branches    34306    34352      +46     
==========================================
+ Hits        31414    31428      +14     
- Misses       4296     4328      +32     
  Partials     1783     1783              

Flag	Coverage Δ
python	92.34% <ø> (ø)
rust	82.92% <47.82%> (-0.08%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[aborgna-q]

Ouch, nice catch -.-'

The HugrInternal delegates look alright, so hopefully this is the only place where this can happen.

[aborgna-q]

I think it's fine to keep this out.
PetgraphWrapper is a thin wrapper over a HugrView, so the default impl should be valid for all implementations.

I'd just leave a comment stating that.