Queue download if update asked per ID

The version of the update function is chosen depending on the URI that is passed to the update method of the repo module:

• An ID URI: the ___worker_update_from_ids is selected, the user will be able to queue the different kara to download by calling again the update method with others ID URI
• Anything else: the ___worker_update is selected. It will download all the database from Kurisu, filtering if the passed URI is not URI_NULL.

The aim here is to offer a download process option which permit the user of doing a simple dry-update and then selecting the different karas he wants to download id per id.

Will close #102 (closed) for now.

Also close some TODOs.

src/database/update.c

@@ -178,7 +178,6 @@ database_update_add(lkt_db *db, const char *kara_path, struct kara_metadata *mdt
                                   "song_number, id, available)"
                                   "SELECT ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?";
     sqlite3_stmt *stmt          = NULL;
-    int ret                     = false;
 
     /* From here we initialize the sqlite stmt. */
 
@@ -191,7 +190,7 @@ database_update_add(lkt_db *db, const char *kara_path, struct kara_metadata *mdt
         (sqlite3_bind_text(stmt, 4, mdt->song_type,   -1, 0) != SQLITE_OK) ||
         (sqlite3_bind_text(stmt, 5, mdt->language,    -1, 0) != SQLITE_OK) ||
         (sqlite3_bind_text(stmt, 6, kara_path,        -1, 0) != SQLITE_OK) ||
-        (sqlite3_bind_int (stmt, 7, 0)                       != SQLITE_OK) ||
+        (sqlite3_bind_int (stmt, 7, (int)avail)              != SQLITE_OK) ||
         (sqlite3_bind_text(stmt, 8, mdt->author_name, -1, 0) != SQLITE_OK) ||
         (sqlite3_bind_int (stmt, 9, mdt->song_number)        != SQLITE_OK) ||
         (sqlite3_bind_int (stmt, 10, (int)id)                != SQLITE_OK) ||
@@ -201,12 +200,14 @@ database_update_add(lkt_db *db, const char *kara_path, struct kara_metadata *mdt
     }
     // clang-format on
 
+    sqlite3_finalize(stmt);
     SQLITE_STEP_DONE(db, stmt, error);
     flush_cache_from_disk(db, kara_path);
-    ret = add_kara_to_update_job(db, id);
+    return avail ? add_kara_to_update_job(db, id) : true;
+
 error:
     sqlite3_finalize(stmt);
-    return ret;
+    return false;
 }
 
 bool