refactor: api_types/helper: Add typing for emoji types as EmojiType.

`EmojiType` specifies types of emoji in the Zulip API.

Author: mkp6781

zulipterminal/api_types.py

@@ -4,6 +4,7 @@
 
 
 EditPropagateMode = Literal['change_one', 'change_all', 'change_later']
+EmojiType = Literal['realm_emoji', 'unicode_emoji', 'zulip_extra_emoji']
 
 
 class PrivateComposition(TypedDict):
@@ -106,7 +107,7 @@ class ReactionEvent(TypedDict):
     type: Literal['reaction']
     op: str
     user: Dict[str, Any]  # 'email', 'user_id', 'full_name'
-    reaction_type: str
+    reaction_type: EmojiType
     emoji_code: str
     emoji_name: str
     message_id: int

zulipterminal/helper.py

@@ -23,9 +23,9 @@
 from urllib.parse import unquote
 
 import lxml.html
-from typing_extensions import Literal, TypedDict
+from typing_extensions import TypedDict
 
-from zulipterminal.api_types import Composition, Message
+from zulipterminal.api_types import Composition, EmojiType, Message
 
 
 MACOS = platform.system() == "Darwin"
@@ -43,7 +43,7 @@ class StreamData(TypedDict):
 
 class EmojiData(TypedDict):
     code: str
-    type: Literal['realm_emoji', 'unicode_emoji', 'zulip_extra_emoji']
+    type: EmojiType
 
 
 NamedEmojiData = Dict[str, EmojiData]