Remove a zone when it got empty

[somangshu]

https://www.notion.so/appsmith/Removing-redundant-zones-8a2cf907c97246adb618664940e298b0

Acceptance Criteria

Scenario 1
Given a zone with only one widget
And the zone is the only zone in the parent section
When I drag the widget out or cut it
Then the zone is removed

Scenario 2
Given a zone with only one widget
And the parent section contains other zones
When I drag the widget out or cut it
Then zone remains in place

Scenario 3
Given a zone with only one widget
And JS is enabled for the zone
When I drag the widget out or cut it
Then zone remains in place