Did some refactor, add YouTube as search variant

bot/handlers/inline_song/on_inline_youtube.py

@@ -0,0 +1,17 @@
+from aiogram import Router
+
+from aiogram.types import InlineQuery
+
+from bot.results.youtube import get_youtube_search_results
+from bot.filters import ServiceSearchFilter
+
+router = Router()
+
+
+@router.inline_query(ServiceSearchFilter('y'))
+async def search_youtube_inline_query(inline_query: InlineQuery):
+    await inline_query.answer(
+        await get_youtube_search_results(inline_query.query.removeprefix('y:')),
+        cache_time=0,
+        is_personal=True
+    )