feat(api): add support for custom API urls following pattern

aiogram/bot/api.py

@@ -92,11 +92,19 @@ def check_result(method_name: str, content_type: str, status_code: int, body: st
     raise exceptions.TelegramAPIError(f"{description} [{status_code}]")
 
 
-async def make_request(session, token, method, data=None, files=None, **kwargs):
+async def make_request(
+    session: aiohttp.ClientSession,
+    token: str,
+    method: str,
+    data=None,
+    files=None,
+    url_pattern: str = API_URL,
+    **kwargs,
+):
     # log.debug(f"Make request: '{method}' with data: {data} and files {files}")
     log.debug('Make request: "%s" with data: "%r" and files "%r"', method, data, files)
 
-    url = Methods.api_url(token=token, method=method)
+    url = Methods.api_url(token=token, method=method, pattern=url_pattern)
 
     req = compose_data(data, files)
     try:
@@ -244,23 +252,25 @@ class Methods(Helper):
     GET_GAME_HIGH_SCORES = Item()  # getGameHighScores
 
     @staticmethod
-    def api_url(token, method):
+    def api_url(token, method, pattern: str = API_URL) -> str:
         """
         Generate API URL with included token and method name
 
         :param token:
         :param method:
+        :param pattern: string with token,method format args
         :return:
         """
-        return API_URL.format(token=token, method=method)
+        return pattern.format(token=token, method=method)
 
     @staticmethod
-    def file_url(token, path):
+    def file_url(token, path, pattern: str = FILE_URL) -> str:
         """
         Generate File URL with included token and file path
 
         :param token:
         :param path:
+        :param pattern: string with token,path format args
         :return:
         """
-        return FILE_URL.format(token=token, path=path)
+        return pattern.format(token=token, path=path)

aiogram/bot/base.py

@@ -25,15 +25,16 @@ class BaseBot:
     _ctx_token = ContextVar('BotDifferentToken')
 
     def __init__(
-            self,
-            token: base.String,
-            loop: Optional[Union[asyncio.BaseEventLoop, asyncio.AbstractEventLoop]] = None,
-            connections_limit: Optional[base.Integer] = None,
-            proxy: Optional[base.String] = None,
-            proxy_auth: Optional[aiohttp.BasicAuth] = None,
-            validate_token: Optional[base.Boolean] = True,
-            parse_mode: typing.Optional[base.String] = None,
-            timeout: typing.Optional[typing.Union[base.Integer, base.Float, aiohttp.ClientTimeout]] = None
+        self,
+        token: base.String,
+        loop: Optional[Union[asyncio.BaseEventLoop, asyncio.AbstractEventLoop]] = None,
+        connections_limit: Optional[base.Integer] = None,
+        proxy: Optional[base.String] = None,
+        proxy_auth: Optional[aiohttp.BasicAuth] = None,
+        validate_token: Optional[base.Boolean] = True,
+        parse_mode: typing.Optional[base.String] = None,
+        timeout: typing.Optional[typing.Union[base.Integer, base.Float, aiohttp.ClientTimeout]] = None,
+        api_url_configs: typing.Tuple[str, str] = (api.API_URL, api.FILE_URL),
     ):
         """
         Instructions how to get Bot token is found here: https://core.telegram.org/bots#3-how-do-i-create-a-bot
@@ -54,6 +55,8 @@ class BaseBot:
         :type parse_mode: :obj:`str`
         :param timeout: Request timeout
         :type timeout: :obj:`typing.Optional[typing.Union[base.Integer, base.Float, aiohttp.ClientTimeout]]`
+        :param api_url_configs: tuple of METHOD,FILE urls
+        :type api_url_configs: :obj:`typing.Tuple[str, str]`
         :raise: when token is invalid throw an :obj:`aiogram.utils.exceptions.ValidationError`
         """
         self._main_loop = loop
@@ -71,6 +74,7 @@ class BaseBot:
         # aiohttp main session
         ssl_context = ssl.create_default_context(cafile=certifi.where())
 
+        self._api_url, self._file_url = api_url_configs
         self._session: Optional[aiohttp.ClientSession] = None
         self._connector_class: Type[aiohttp.TCPConnector] = aiohttp.TCPConnector
         self._connector_init = dict(limit=connections_limit, ssl=ssl_context)
@@ -197,8 +201,18 @@ class BaseBot:
         :rtype: Union[List, Dict]
         :raise: :obj:`aiogram.exceptions.TelegramApiError`
         """
-        return await api.make_request(self.session, self.__token, method, data, files,
-                                      proxy=self.proxy, proxy_auth=self.proxy_auth, timeout=self.timeout, **kwargs)
+        return await api.make_request(
+            self.session,
+            self.__token,
+            method,
+            data,
+            files,
+            proxy=self.proxy,
+            proxy_auth=self.proxy_auth,
+            timeout=self.timeout,
+            url_pattern=self._api_url,
+            **kwargs,
+        )
 
     async def download_file(self, file_path: base.String,
                             destination: Optional[base.InputFile] = None,
@@ -237,7 +251,9 @@ class BaseBot:
         return dest
 
     def get_file_url(self, file_path):
-        return api.Methods.file_url(token=self.__token, path=file_path)
+        return api.Methods.file_url(
+            token=self.__token, path=file_path, pattern=self._file_url,
+        )
 
     async def send_file(self, file_type, method, file, payload) -> Union[Dict, base.Boolean]:
         """