Stop detecting longform Optional expression types.

[dfed]

In #77, I added code to find Optional<Generic>.self and treat the reference as Generic?.self. This detection was added so that we could throw an error when fulfillingAdditionalTypes was written as a longform optional (Optional<Generic>) rather than a shortform optional (Generic?).

However, this detection can be wrong. If someone were to define a nested Optional type and then refer to it in fulfillingAdditionalTypes without qualification, we'd parse it incorrectly. Fixing this issue would require having locally defined type context at the var typeDescription: TypeDescription scope, which isn't feasible.

While this particular issue is likely quite rare, it's not worth introducing this kind of trap door in order to protect consumers from trying to fulfillingAdditionalTypes with a longform optional: there are all kinds of potential fulfillingAdditionalTypes failures—like fulfilling non-subclassable concrete types—that we do not error on because we do not have enough information to detect it.

I also updated placement of return while I was here.

[codecov]

Codecov Report

Attention: Patch coverage is 92.30769% with 2 lines in your changes missing coverage. Please review.

Project coverage is 99.91%. Comparing base (1d19827) to head (37be0f5).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
Sources/SafeDICore/Models/TypeDescription.swift	92.30%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #135      +/-   ##
==========================================
- Coverage   99.91%   99.91%   -0.01%     
==========================================
  Files          32       32              
  Lines        3475     3467       -8     
==========================================
- Hits         3472     3464       -8     
  Misses          3        3              

Files with missing lines	Coverage Δ
Sources/SafeDICore/Models/TypeDescription.swift	99.56% <92.30%> (-0.01%)	⬇️