text: Title: [ENH] detection notebook - move data loading for examples to functions in the `datasets` module
  Body: In the detection notebook 7 (added in https://github.com/sktime/sktime/pull/7284), @alex-jg3 has used a couple common toy data sets to demonstrate the detectors.
  
  The data is loaded manually, but it would be nice to have a `load_datasetname` function for each, and proper documentation.
  
  As a recipe:
  
  1. look at every block in the notebook 7, where a csv is loaded
  2. try to turn this into a function `load_dataname(param1, param2)`. Possibly with a `return_mtype` argument that allows the user to specify the format, using `convert` from `datatypes`, but this is optional.
  3. obtain the description of the dataset from this readme https://github.com/sktime/sktime-tutorial-ODSC-Europe-2024/blob/main/data/README.md and include it in the docstring
  4. put the function in the appropriate location in the `datasets` module