[mlir][shape] Add shape.lib attribute

[mlir][shape] Add shape.lib attribute

Enable querying shape function library ops from the module. Currently
supports singular or array of them (as long as array has all unique ops
in mappings). The preferred canonical form would have one library, but
given the invariant on the mapping, this can easily be achieved by a
simple merging pass.

Preferred the attribute approach vs naming convention as these could be
added in multiple different ways.