Add support for bridging spoilers

mautrix_telegram/formatter/from_matrix/parser.py

@@ -95,5 +95,8 @@ class MatrixParser(BaseMatrixParser[TelegramMessage]):
     async def color_to_fstring(self, msg: TelegramMessage, color: str) -> TelegramMessage:
         return msg
 
-    async def spoiler_to_fstring(self, msg: TelegramMessage, spoiler: str) -> TelegramMessage:
+    async def spoiler_to_fstring(self, msg: TelegramMessage, reason: str) -> TelegramMessage:
+        msg = msg.format(self.e.SPOILER)
+        if reason:
+            msg = msg.prepend(f"{reason}: ")
         return msg

mautrix_telegram/formatter/from_matrix/telegram_message.py

@@ -29,6 +29,7 @@ from telethon.tl.types import (
     MessageEntityMention as Mention,
     MessageEntityMentionName as MentionName,
     MessageEntityPre as Pre,
+    MessageEntitySpoiler as Spoiler,
     MessageEntityStrike as Strike,
     MessageEntityTextUrl as TextURL,
     MessageEntityUnderline as Underline,
@@ -55,6 +56,7 @@ class TelegramEntityType(Enum):
     MENTION = Mention
     MENTION_NAME = InputMentionName
     COMMAND = Command
+    SPOILER = Spoiler
 
     USER_MENTION = 1
     ROOM_MENTION = 2