Add support for compiled patterns in Filters.regex (#468)

* Add support for compiled patterns in Filters.regex and remove extra whitespaces

* Update filters.py

Co-authored-by: Dan <14043624+delivrance@users.noreply.github.com>

pyrogram/client/filters/filters.py

@@ -17,7 +17,7 @@
 #  along with Pyrogram.  If not, see <http://www.gnu.org/licenses/>.
 
 import re
-from typing import Callable
+from typing import Callable, Union
 
 from .filter import Filter
 from ..types import Message, CallbackQuery, InlineQuery
@@ -296,7 +296,7 @@ class Filters:
         )
 
     @staticmethod
-    def regex(pattern: str, flags: int = 0):
+    def regex(pattern: Union[str, re.Pattern], flags: int = 0):
         """Filter updates that match a given regular expression pattern.
 
         Can be applied to handlers that receive one of the following updates:
@@ -309,8 +309,8 @@ class Filters:
         stored in the ``matches`` field of the update object itself.
 
         Parameters:
-            pattern (``str``):
-                The regex pattern as string.
+            pattern (``str`` | ``Pattern``):
+                The regex pattern as string or as pre-compiled pattern.
 
             flags (``int``, *optional*):
                 Regex flags.
@@ -331,7 +331,11 @@ class Filters:
 
             return bool(update.matches)
 
-        return create(func, "RegexFilter", p=re.compile(pattern, flags))
+        return create(
+            func,
+            "RegexFilter", 
+            p=pattern if isinstance(pattern, re.Pattern) else re.compile(pattern, flags)
+        )
 
     # noinspection PyPep8Naming
     class user(Filter, set):