[roll] Roll fuchsia [fuchsia-controller] Delete dynamic Python FIDL bindings

The approach for this change was the following:

- Delete fidl._import which contains the import hooks for the fidl
  module.
- Delete all fuchsia-controller tests that correspond to duplicate tests
  covered by fidlgen_python.
- Modify all remaining uses of fidl imports. Some stopped working purely
  because the import hook is not present.
- Move get_fidl_ir_map() into fidl.ir module.
- Move ProtocolMarker into fidl._fidl_common as FidlProtocolMarker
- Delete fidl._library and fidl._import
- Delete importing.py tests. Some of these were more than just testing
  import hooks, but they're all covered by fidlgen_python tests.
- Rename the GIDL fuchsia-controller backend to python.

The dynamic Python FIDL bindings provided a template for me to write the
bindings for fidlgen_python. For that, I'm grateful to the authors of
the original dynamic bindings.

Original-Bug: 325654974
Original-Fixed: 355717613
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1249187
Original-Revision: c6372f9d145959ebf357fe74ca5de514ea11cb78
GitOrigin-RevId: 47e7f79092235f6c71a522c72a693c81f5a8ffd0
Change-Id: Ia4b8798d512117850242fbf77e0e0f5c5808fd02