[Feature Request] Add a `type` builtin

[yuanjv]

Bug Description

type() is not in mojo

Steps to Reproduce

when print(type) was run, the expected output is "<class 'type'>" but the actual output is "error: Expression: use of unknown declaration 'type'".

Context

[czheo]

Unfortunately you need to do something like this at this point

let py = Python.import_module("builtins")
py.print(py.type) # <class 'type'>

[Mogball]

The issue with adding the type bultin to Mojo is that we don't have a runtime type representation yet. I.e. in Python, type returns a type instance that can be used like a class.

[DayDun]

As a temporary workaround, maybe it could return a string representation of the type? Being able to debug types more easily would be very handy.