apply patch #95861 to remove trigger dependency for MySQL.

Add full referential integrity to AlbumRoots, Albums, Images and Tags
tables entries.
Provide the equivalent behaviour to the triggers using ON DELETE and
ON UPDATE in FOREIGN KEY references.

Use dbaction to perform database specific preparation for migration.

The MySQL schema has a circular dependency and this must be removed
before any leftover contents of the database are removed prior to the
migration. No actions are required for SQLite

Referential integrity in MySQL does not allow the Albums.icon field
to be set prior to the Images table being populated. Use a fake
AlbumsExtra table to copy over the icons data.
Note we use the same procedure for both SQLite and MySQL to ensure
that migration is possible between any combination of databases.

CCBUGS: 355831