[LABS-126] Add label support to /add_key (#20098)

Add label support

Author: Quexington

chia/wallet/wallet_request_types.py

@@ -125,6 +125,7 @@ class GenerateMnemonicResponse(Streamable):
 @dataclass(frozen=True)
 class AddKey(Streamable):
     mnemonic: list[str]
+    label: Optional[str] = None
 
 
 @streamable

chia/wallet/wallet_rpc_api.py

@@ -810,7 +810,7 @@ async def generate_mnemonic(self, request: Empty) -> GenerateMnemonicResponse:
     async def add_key(self, request: AddKey) -> AddKeyResponse:
         # Adding a key from 24 word mnemonic
         try:
-            sk = await self.service.keychain_proxy.add_key(" ".join(request.mnemonic))
+            sk = await self.service.keychain_proxy.add_key(" ".join(request.mnemonic), label=request.label)
         except KeyError as e:
             raise ValueError(f"The word '{e.args[0]}' is incorrect.")