Include TWDTW classification in sits

[gilbertocamara]

Describe the new API function requested
Include the new version of the dtwSat package by @vwmaus in sits. The previous version of dtwSat used the S4 model, which made it difficult to integrate the algorithm in sits. The new version uses S3, thus making the integration of dtwSat into sits.

Associated sits API function
Develop a new sits_dtw() that can be used in connection with sits_train().

[vwmaus]

Implementation steps:

• Build a test set
• Create a new method in dtwSat that supports inputs from sits and returns a twdtw_knn1 model. The new method is expected in dtwSat CRAN release 1.0-2.
• Integrate the twdtw_knn1 to sits_twdtw()

[OldLipe]

Move this issue to #1099.