[5.x]: Add "enable / disable" options for "all sites" in quick actions

[RienMoeyaert]

Description

To enable / disable a variant of a product across all sites in a multi-site setup, several steps are needed:

• open detail of variant
• open the side status bar by clicking the 3 dots
• flip the toggle for "enabled for all sites"

This is a bit hidden for users if they're not aware the change only happens on the active site.

If you change the status of the variant using the quick action, it is not specified if it's only for the active site or for all sites.

Suggestion

Add more quick actions in the "set status" dropdown:

• enable for all sites
• disable for all sites