[RFC] Rename Hybrid Script

Development pre-RFC
10

There are some tradeoffs, for example, given the type system is shared across relay and tir. We might in the future have things like

@tvm.script
class MixedModule:
    MyStruct = ADT[Integer, Integer]    

    def relay_func(x: ty.Tensor):
         return relay.call_tir_dest_passing(tir_func, x)
   
     def tir_func(x: ty.handle)

So parsing might need to go beyond the function level. Additionally, we might also need to serialize the meta-data.

Conceptually, the basic unit in the transformation is an IRModule, and it would be nice to have a decorator on a module to support that(although it is also important to decorate a function as well)