fix: fold parenthesized type(X).max/min in IR generation

[innbuld]

Summary

(type(uint8)).max (redundant parentheses around type(X)) fails IR generation, while the non-parenthesized type(uint8).max works fine:

$ slither A.sol
Failed to generate IR for Test.test ...
slither.slithir.exceptions.SlithIRError: type(uint8).max is unknown

Root cause

type(X).max/.min is folded to a constant in ExpressionToSlithIR._post_member_access, but the check required the accessed sub-expression to be a bare CallExpression. Parentheses wrap the type() call in a single-element TupleExpression, so the fold is skipped. The member access then falls through to convert.py's _convert_type_contract (which only handles creationCode/runtimeCode/interfaceId/name) and raises type(X).max is unknown.

Fix

Unwrap redundant single-element parentheses before the type(X).max/.min check. (type(X)).max, ((type(X))).min, etc. now fold to the correct constant like the non-parenthesized form (elementary signed and unsigned types covered).

Testing

• New unit test tests/unit/slithir/test_type_minmax.py asserts the folded constants for uint8/uint256/int256, parenthesized and nested, plus the plain form as a regression guard. It fails before the fix (type(uint8).max is unknown) and passes after.
• Existing tests/unit/slithir and solc_parsing minmax tests pass.

Fixes #2645