Match attributes in input pattern.

Bind attributes similar to operands. Use to rewrite leakyreulo and const rewrite pattern. The attribute type/attributes are not currently checked so should only be used where the attributes match due to the construction of the op.

To support current attribute namespacing, convert __ in attribute name to "$" for matching purposes ('$' is not valid character in variable in TableGen).

Some simplification to make it simpler to specify indented ostream and avoid so many spaces. The goal is not to have perfectly formatted code generated but good enough so that its still easy to read for a user.

PiperOrigin-RevId: 228183639