Fix null values in DB (#2840)

* Fix album image_files being null.

* Fix small nitpick.

* Use ExecContext instead of Exec.

* Change more columns to not null and set default values.

* Remove columns that don't need to be changed from migration.

* Fix typo.

* Remove unnecessary select statements.

* Remove duplicate code.

* Do not apply changes to radio table.

* Do not apply changes full_text columns and respective indexes.

* Fix musicbrainz columns.

* Rename migration.

* Make ExternalInfoUpdatedAt nullable

* Make Share's timestamps nullable

---------

Co-authored-by: Deluan Quintão <deluan@navidrome.org>

utils/gg/gg.go

@@ -30,3 +30,17 @@ func FirstOr[T comparable](or T, values ...T) T {
 	// If all the input values are zero, return the default value.
 	return or
 }
+
+// P returns a pointer to the input value
+func P[T any](v T) *T {
+	return &v
+}
+
+// V returns the value of the input pointer, or a zero value if the input pointer is nil.
+func V[T any](p *T) T {
+	if p == nil {
+		var zero T
+		return zero
+	}
+	return *p
+}