Add more validation and checks to MLOps

[tmart234]

Right now there are bugs with the one-shot encoding of station ids into the dataset.

• We need to make sure that we check dataset Columns for being correct. Some columns are stations for the encoding and these should be checked against MLRivers.txt
• Echo out vars used for models's input size (shape) and be able to feed to release stage GitHub action (needed there)
• Validation in a separate module!