Verification & Validation: Add three states for running the validation

The statuses would be managed with system properties and extend the current on/off switch we have.
It will be possible to change the status for each validation check type. Check types are for example redundancy, range, missing columns.

• Reactive
  The "normal way" you make a change and the verification runs instantly
• Off
  Verification is disabled
• On demand
  Verification only runs when requested. Can be useful for large dtables where you for example change every value in a column and just really care about the verification status after all the changes.

Few ideas to think about:

1. Might be worth it to also store the state per dtable.
2. If V&V runs for over X amount of seconds. Ask if the user wants to change the setting from "Reactive" to "On Demand" for this table.