fix(python): gate same-class-method resolution on localBound shadow guard

[GertL]

Summary

• resolveCall and valueRefTarget in the Python extractor checked currentMethods() (same-class method/property match) before the localBound shadow guard, so the guard only protected the same-module fallback branch.
• This produced false RelCalls/value-ref edges for the extremely common self.x = x constructor idiom whenever the class also defines a property/method literally named x (e.g. a SQLAlchemy synonym property) — the RHS x is the parameter, not a self-reference.
• Moved the localBound check to run first in both functions, so it gates every branch, not just the same-module fallback.

Verification

• Added TestAST_ConstructorParamShadowsSynonymProperty, modeled on a real false positive found in Apache Airflow's DagRun.__init__ / state synonym property.
• Confirmed against the actual Airflow checkout, both via direct extractor invocation and via enola --generate: pre-fix produces a false calls -> DagRun.state edge from DagRun.__init__; post-fix it's gone, with the correct real edges (is_arg_set, utcnow, new_dagrun_trace_carrier) unaffected.
• go test ./..., go vet, gofmt all clean.