Feature: validation column config

[louisdorard]

More info in associated Shortcut story. Additional info:

• Added documentation to replay and apply edits methods
• Fixed bug with boolean editable columns (which includes validation columns): missing values were transformed into True!

How to switch to this new version of the plugin: in all projects that use validation columns...

• In the Flow
  • Change your editlogs to use "validated" instead of the validation column name that was previously used
  • Build all datasets downstream
• In the Visual Webapp
  • Remove upstream recipe/step previously used to create a validation column
  • Remove previous validation column name from editable columns
  • Add to settings that validation column is required