Allow users to upload and use own data for test and training dataset:
[ ] in dataset collection step, add a selection: "Upload own training and testing data separately" to enable uploading of own training and testing dataset
[ ] if training dataset is invalid, say why
[ ] possibly: create a dataset from it in the fitting form (depends on #16)
[ ] possibly: create training and testing dataset sampleid lists (depends on #16)
[ ] use training dataset for continuing steps of the model version creation
[ ] use test dataset for continuing steps of the model version creation
Allow users to upload and use own data for test and training dataset: