Add a new data model for training the predictor model

[vishesh-baghel]

This is needed because the native query in the mindsdb editor is not working as expected. I am continuously getting errors while training the model. Fortunately I understood the reason why I was getting the errors.

I was trying to run the MongoDB native query as db.collection.find({}, {commits: 0}) but the commits array was not being excluded. I finally decided to keep the query as db.collection.find({}) and to make a new model which doesn't have the commits array.

The model's training completed successfully. I think the mindsdb's lightwood ai model doesn't process the dictionaries or arrays as a datatype for a column while training a regression model.

[vishesh-baghel]

Added the new training model as: TrainingFileSchema { installationId, owner, repoName, filePath, numberOfCommits, riskScore }