Add size to album details (#561)

* add size to album details

for #534

* addressing review comments:

* create index album(size)
* remove unneeded Size field from refresh struct
* add whitespace to album details
* add size to album list view

* prettier

db/migration/20201010162350_add_album_size.go

@@ -0,0 +1,30 @@
+package migration
+
+import (
+	"database/sql"
+
+	"github.com/pressly/goose"
+)
+
+func init() {
+	goose.AddMigration(Up20201010162350, Down20201010162350)
+}
+
+func Up20201010162350(tx *sql.Tx) error {
+	_, err := tx.Exec(`
+alter table album
+	add size integer default 0 not null;
+create index if not exists album_size
+	on album(size);
+	`)
+	if err != nil {
+		return err
+	}
+	notice(tx, "A full rescan will be performed to calculate album sizes.")
+	return forceFullRescan(tx)
+}
+
+func Down20201010162350(tx *sql.Tx) error {
+	// This code is executed when the migration is rolled back.
+	return nil
+}