Add discrete fourier transform as an `AutoEumlateTransform`

[sgreenbury]

Contributes towards #513.

This PR adds:

• DiscreteFourierTransform subclassing AutoEmulateTransform
• Example usage in exploratory notebook comparing with PCA

[review-notebook-app[bot]]

Check out this pull request on 

See visual diffs & provide feedback on Jupyter Notebooks.

---

Powered by ReviewNB

[codecov-commenter]

Codecov Report

:x: Patch coverage is 96.32353% with 5 lines in your changes missing coverage. Please review. :white_check_mark: Project coverage is 80.39%. Comparing base (cecf95d) to head (d4456c7).

Files with missing lines	Patch %	Lines
...mulate/experimental/transforms/discrete_fourier.py	93.75%	3 Missing :warning:
autoemulate/experimental/compare.py	80.00%	2 Missing :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #655      +/-   ##
==========================================
+ Coverage   80.20%   80.39%   +0.19%     
==========================================
  Files         155      157       +2     
  Lines       11132    11259     +127     
==========================================
+ Hits         8928     9052     +124     
- Misses       2204     2207       +3     

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

:rocket: New features to boost your workflow:

• :snowflake: Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[github-actions[bot]]

Coverage report

Click to see where and how coverage changed

File	Statements	Missing	Coverage	Coverage (new stmts)	Lines missing
autoemulate/experimental
compare.py					294-299
autoemulate/experimental/transforms
__init__.py
discrete_fourier.py					157-162
tests
test_compare.py
tests/experimental/transforms
test_discrete_fourier.py
test_serde.py
test_transforms.py
Project Total

This report was generated by python-coverage-comment-action