[EICNET-2972]feat: Add queue to remove items + check if there is media to remove + sensitive permission

[Dromadoros]

How to test:

Delete group and his content by queue

• Get a group where you have a lot of content in it
• Delete the group (keep an eye about some content title to see if it has not been removed directly)
• Normally content should not be delete on the group delete action
• Wait for cron or trigger it (drush core:cron)
• Verify content has been removed

Sensitive deletion

• Change a group visibility to sensitive
• Verify you can still delete the group

Delete media when it's only used once

• Add a document to a group with a new media in it
• Delete the group
• Run cron
• Verify document has been removed and also the media

[lramarojaona]

@Dromadoros , here I think we should be generic:

• Search for any entity reference field
• For each Media entity reference, look if it's being used somewhere else
• If not, delete the media

[lramarojaona]

@Dromadoros ,
It works, but please see my comment