Implement Pattern module

[masa10-f]

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• Make sure you have tests for the new code and that test passes (run pytest)
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• Type checking by mypy and pyright
• Make sure the checks (github actions) pass.
• Check that the docs compile without errors (run make html in ./docs/ - you may need to install dependency for sphinx docs, see docs/requirements.txt.)

Implemented pattern module, which contains two pattern classes and helper functions.

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[Copilot]

Pull Request Overview

This PR introduces the new pattern module with two pattern classes and accompanying helper functions while updating tests and documentation.

• Adds tests for MutablePattern covering initialization, command addition (including error cases), and space calculations.
• Updates documentation to include references and detailed module docs for the new pattern module.

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
tests/test_pattern.py	Added tests to validate the functionality of the new MutablePattern methods.
docs/source/references.rst	Updated the module reference list to include the new pattern module.
docs/source/pattern.rst	Added documentation for pattern module classes and helper functions using autodoc.

Comments suppressed due to low confidence (1)

tests/test_pattern.py:58

• [nitpick] Consider removing the main invocation of pytest; tests are usually executed via the pytest CLI, which can help avoid unintended side effects.

    pytest.main()

[masa10-f]

Memo: I should update the pattern check rules