User input validation

[msokoloff1]

• The goal of this PR is to check user input to the sdk. There are a few places where customer input fails and it isn't clear exactly what caused the error to occur

• There was a bit of scope creep and a few other things got pulled in. It is kind of a large PR sorry.

• Overivew of changes:

  • datarows now support image_overlay metadata type
  • Checks if metadata type is a valid when adding metadata to a data row
  • Fixes the dataset.data_rows_for_external_id bug.
    • Previously we would throw an error if a user has more than one data row with the same external id
  • Add warnings to deprecated functions
  • Supports webhook topics for reviews
  • Now checks if webhook topics are valid
  • Validate labeling parameter overrides args
  • Validates upsert_review_queue args
  • Improved / more descriptive doc strings

[nmaswood]

will take another look first thing tmr :)