feat!: Add implicit importing of modules

[mark-koch]

Closes #133 and closes #462.

• When using implicit modules, automatically import definitions by inspecting the __dict__ of the containing Python module.
• Implicit modules are no longer discarded once they are compiled for the first time.
• Updated examples to use implicit modules

BREAKING CHANGE: guppy.take_module renamed to guppy.get_module and no longer removes the module from the state.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 95.45455% with 2 lines in your changes missing coverage. Please review.

Project coverage is 92.00%. Comparing base (ce0f746) to head (f943fe8).

Files with missing lines	Patch %	Lines
guppylang/decorator.py	92.85%	2 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #461 +/- ## ========================================== + Coverage 91.91% 92.00% +0.08% ========================================== Files 58 58 Lines 5891 5900 +9 ========================================== + Hits 5415 5428 +13 + Misses 476 472 -4 ```

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