Structure update

[blizzz]

As a process owner, I want to be able to work on a table structure on a cloned table, and only when my changes are ready, apply them on the production table. The cloned table might be a re-imported table on the same instance, or on a staging instance.

Furthermore, I want to be able to do the same against Applications/Context.

With #2598 we have unique identifiers of columns, selection options and views, that are abound to the parent table. With this we can identify these elements across instances and even local tables. When exporting and importing a table structures, the UUID are kept in place.

There is prior work at #2504 which was based on a tables version without UUIDs, and could not work in a satisfactory way. Maybe some parts of the PR still can be re-used, perhaps the UI.

What needs to be done:

• Front-end wise
  • allow a table manager to import a scheme from a json file onto the selected table
  • allow an application manager to export the scheme of an application
  • allow an application manager to import a scheme from a json file onto the selected table
  • on importing, the application or table manager should be able to see the changes, and exclude the ones they do not want to import
• Backend wise
  • resolve changes between the original and the uploaded table structure
  • resolve changes between the original and the uploaded application structure
  • apply selected changes against the specified table
  • apply selected changes against the specified application

The focus is first on importing against a table. Updating the application structure is a second step.