Support the Editing API v2

[clepski]

Is your feature request related to a problem? Please describe. As a plugin developer I want to use the Editing API v2.

Describe the solution you'd like Open SCD should support the Editing API v2.

Requirements

• Edit Events conforming to API v2 should be applied the SCD file and create the usual history entries

Suggestions for a specific user interaction

The code for the API v2 is already present in the old Editing Mixin, see https://github.com/openscd/open-scd/blob/main/packages/core/mixins/Editing.ts We should transfer this code to the Editor Addon https://github.com/openscd/open-scd/blob/main/packages/openscd/src/addons/Editor.ts and support both Editing v1 and v2. The editing code needs to be tested.