add last fm similar artists to db table

+ add db methods for the above
+ try and discard last fm store

app/db/sqlite/queries.py

@@ -26,7 +26,14 @@ CREATE TABLE IF NOT EXISTS settings (
     root_dirs text NOT NULL,
     exclude_dirs text,
     artist_separators text
-)
+);
+
+CREATE TABLE IF NOT EXISTS lastfm_similar_artists (
+    id integer PRIMARY KEY,
+    artisthash text NOT NULL,
+    similar_artists text NOT NULL,
+    UNIQUE (artisthash)
+);
 """
 
 CREATE_APPDB_TABLES = """
@@ -58,8 +65,6 @@ CREATE TABLE IF NOT EXISTS albums (
     UNIQUE (albumhash)
 );
 
-
-
 CREATE TABLE IF NOT EXISTS artists (
     id integer PRIMARY KEY,
     artisthash text NOT NULL,