fix: Injector plugin requires all annotations in the injected function

[Daverball]

Closes: #188
Closes: #189

This also switches to using lookup_full_name

[codecov]

Codecov Report

Attention: Patch coverage is 75.00000% with 2 lines in your changes missing coverage. Please review.

Project coverage is 96.5%. Comparing base (7621d51) to head (aaeb5ea).
Report is 92 commits behind head on main.

Files with missing lines	Patch %	Lines
flake8_type_checking/checker.py	75.0%	2 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##            main    #201     +/-   ##
=======================================
- Coverage   98.7%   96.5%   -2.3%     
=======================================
  Files          3       4      +1     
  Lines        482     980    +498     
=======================================
+ Hits         476     946    +470     
- Misses         6      34     +28     

Files with missing lines	Coverage Δ
flake8_type_checking/checker.py	96.2% <75.0%> (-2.4%)	⬇️

... and 1 file with indirect coverage changes