Add HTMLParser compatibility to recursive Matrix parser and remove old parser

mautrix_telegram/formatter/from_matrix/html_reader.pyi

@@ -0,0 +1,11 @@
+from typing import Dict, List
+
+
+class HTMLNode(List['HTMLNode']):
+    tag: str
+    text: str
+    tail: str
+    attrib: Dict[str, str]
+
+
+def read_html(data: str) -> HTMLNode: ...