[ENH] Implement U-Shapelets clusterer

[MatthewMiddlehurst]

Describe the feature or idea you want to propose

It would be nice to have an implementation of the Unsupervised Shapelets (U-Shapelets)

https://ieeexplore.ieee.org/document/6413851
https://epubs.siam.org/doi/pdf/10.1137/1.9781611974010.101
https://link.springer.com/article/10.1007/s10618-015-0411-4

Describe your proposed solution

Implement the U-Shapelets algorithms and possibly scalability improvements. It will be on the contributor to evaluate the accuracy of their implementation to published code and results.

Describe alternatives you've considered, if relevant

No response

Additional context

No response

[aryanpola]

@aeon-actions-bot assign @aryanpola