Support cross-references with arg types but no contract prefix

[james-toussaint]

Following

• Fix & normalize doc references openzeppelin-contracts#6696 (review)

Issue

Cross-references with arg types but no contract prefix — {fn-argtype} — don't resolve, which forces {Contract-fn-argtype} even for unambiguous self-contract links. The AsciiDoc pipeline already supports the bare form (via contract.hbs's :{{fullname}}: local attribute), so this is a parity gap.

Note: bare {fn} (no arg types) does resolve today — it's specifically the arg-typed prefix-less form that fails.

Sample

Supported ✅

/// @dev Parses [...]. See {ERC4337Utils-packValidationData-address-uint48-uint48}.

Not supported yet ❌ (renders as literal packValidationData-address-uint48-uint48)

/// @dev Parses [...]. See {packValidationData-address-uint48-uint48}.