feat(tags): add minimum vote count for top tags & provide official tags

Add configuration: `BEATMAP_TAG_TOP_COUNT` to control the minimun vote count

Tips: this is 10 in osu-web, but private server doesn't have enough player so we use 2 as default value

Official tags see: https://osu.ppy.sh/wiki/Beatmap/Beatmap_tags

app/config.py

@@ -149,6 +149,7 @@ class Settings(BaseSettings):
     enable_all_beatmap_leaderboard: bool = False
     enable_all_beatmap_pp: bool = False
     seasonal_backgrounds: Annotated[list[str], BeforeValidator(_parse_list)] = []
+    beatmap_tag_top_count: int = 2  # this is 10 in osu-web
 
     # 谱面缓存设置
     enable_beatmap_preload: bool = True