fix: allow both _composable_pass and composable_pass imports

[CalMacCQ]

resolves breakage in #2962 by allowing both from _composable_pass and from composable_pass imports. This is a problem as in tket-py we access the private module _composable_pass for the implementation of PytketHugrPass (not the best practice on my part).

I've added a duplicate _composable_pass.py file now with a wildcard import (gross)

Will remove this once we have _composable_pass usage removed from tket-py. There shouldn't be any _scope usage in the tket-py main branch.

Theres probably a nicer way to do this with something like

import sys
sys.modules["_foo"] = sys.modules[__name__]

However this wasn't immediately working for me.

Related #2961

[CalMacCQ]

I'm on holiday tomorrow so feel free to edit/merge in my absence if need be.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 83.87%. Comparing base (856f92d) to head (badc4d2).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2965   +/-   ##
=======================================
  Coverage   83.87%   83.87%           
=======================================
  Files         267      268    +1     
  Lines       52943    52945    +2     
  Branches    46857    46857           
=======================================
+ Hits        44408    44410    +2     
  Misses       6266     6266           
  Partials     2269     2269           

Flag	Coverage Δ
python	88.84% <100.00%> (+<0.01%)	⬆️

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[CalMacCQ]

Added this extra line to test that you can actually use both import paths.