Replace old used-to-be-GORM datastructures (#104305) with sqlc-generated
structs. This also makes it possible to use more specific structs that
are more taylored to the specific queries, increasing efficiency.
This commit mostly deals with workers, including the sleep schedule and
task scheduler.
Functional changes are kept to a minimum, as the API still serves the
same data.
Because this work covers so much of Flamenco's code, it's been split up
into different commits. Each commit brings Flamenco to a state where it
compiles and unit tests pass. Only the result of the final commit has
actually been tested properly.
Ref: #104343
GORM implicitly sets 'created at', 'updated at' and 'deleted at' timestamps
to 'now' by calling a 'now function'. This is now implemented by Flamenco
directly, instead of relying on GORM.
Ref: #104305
This also corrects the sleep schedule schema to actually store the
`is_active` field as `boolean` (it was `numeric`, which is the same
underlying field type in SQLite, but produces a different struct field
in the sqlc-generated Go code).
Ref: #104305
Workers can be soft-deleted, which means that they stay in the database.
As such, foreign key constraints `ON DELETE CASCADE` do not trigger, and
thus their sleep schedule can still be active. This is now detected and
handled gracefully.
