Add sync versions of stream and save methods (#215)

* Add sync versions of stream and save methods

In order to provide synchronous interface to the library

* Fix save_sync() failing to use metadata_fname and fix typing issues

Signed-off-by: rany <ranygh@riseup.net>

---------

Signed-off-by: rany <ranygh@riseup.net>
Co-authored-by: rany <ranygh@riseup.net>

examples/sync_audio_generation_in_async_context.py

@@ -0,0 +1,36 @@
+#!/usr/bin/env python3
+
+"""
+This example shows that sync version of save function also works when run from 
+a sync function called itself from an async function.
+The simple implementation of save_sync() with only asyncio.run would fail in this scenario, 
+that's why ThreadPoolExecutor is used in implementation.
+
+"""
+
+import asyncio
+
+import edge_tts
+
+TEXT = "Hello World!"
+VOICE = "en-GB-SoniaNeural"
+OUTPUT_FILE = "test.mp3"
+
+
+def sync_main() -> None:
+    """Main function"""
+    communicate = edge_tts.Communicate(TEXT, VOICE)
+    communicate.save_sync(OUTPUT_FILE)
+
+
+async def amain() -> None:
+    """Main function"""
+    sync_main()
+
+
+if __name__ == "__main__":
+    loop = asyncio.get_event_loop_policy().get_event_loop()
+    try:
+        loop.run_until_complete(amain())
+    finally:
+        loop.close()