fix: broaden unsigned comparison rule and avoid cast false positives

[9iang22]

Catch additional unsigned types (uint*_t) while excluding signed-cast comparisons

We will cast an unsigned int to a signed one and then compare it with zero to see if there is overflow, but Semgrep can not detect the type cast with typed metavariable.

The following code raises an FP in the original rule with the pattern like (size_t $E) >= 0.

size_t a;
if ((int32_t) a >=0) {...}

PS: It seems like a bug in the Semgrep engine, but whatever, I set a whitelist pattern here to avoid such FP.

[0xdea]

Thank you for the PR. Let me think some more about this one.

[9iang22]

The current version also not support typedef, but I don't know how to handle it with Semgrep gracefully.