Task: Tests for DnD sagas.

[marks0351]

Unit Tests:
Test: anvilDraggingSagas
New Widget DnD

• adds new widget on to the main canvas
• adds new widget into an existing section
• adds new widget into an existing zone
• triggeres anvil updates and recomputes zone count and space distribution on saving the dsl
• selects newly added widget after adding it to the canvas

Move exitsing Widgets DnD

• move widget on to the main canvas
• move widget on to an existing section
• move widget on to an existing zone
• triggeres anvil updates and recomputes zone count and space distribution on saving the dsl
• handles multiple widgets moved at once