Add checks for generic types and discard any unexpected types

[sschr15]

Fixes #409 by adding checks and discarding any clearly bogus generics

[github-actions]

Test Results

   18 files  ±0     18 suites  ±0   1m 4s ⏱️ -1s
1 930 tests +1  1 929 ✅ +1  1 💤 ±0  0 ❌ ±0 
2 556 runs  +2  2 554 ✅ +2  2 💤 ±0  0 ❌ ±0 

Results for commit 1c14529. ± Comparison against base commit fd167c7.

♻️ This comment has been updated with latest results.

[SpaceWalkerRS]

How do these checks work when signatures depend on each other? For example, a field that initially has a valid signature, but its type class's signature does not pass the check and is modified/removed, which in turn then invalidates that field's signature.