Cells: Fix loose foreign key trigger validation routine

What does this MR do and why?

It appears that the spec to ensure that triggers are installed were not properly implemented skipping checking the missing trigger as required by loose foreign key implementation.

This breaks down that into missing and extraneous triggers check.

Related to:

• #388275 (closed)
• !108452 (merged)
• Discovered by @manojmj

Fix data

• Add missing track_record_deletions
• Nullify push_rule_id on application_settings if missing
• Do not touch tags, since we do not remove it ever

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.