Add PCA Dictionary Indexing

[ZacharyVarley]

Description of the change

Add fast PCA dictionary indexing

Progress of the PR

• [ ] Docstrings for all functions
• [ ] Unit tests with pytest for all lines
• [ ] Clean code style by running black via pre-commit

For reviewers

• [ ] The PR title is short, concise, and will make sense 1 year later.
• [ ] New functions are imported in corresponding __init__.py.
• [ ] New features, API changes, and deprecations are mentioned in the unreleased section in CHANGELOG.rst.
• [ ] New contributors are added to release.py, .zenodo.json and .all-contributorsrc with the table regenerated.