Adds the ability to easily reset the encoder

The initialize function is also refactored to use the clear function to reduce code duplication as they would be doing the same thing.

irctokens/stateful.py

@@ -24,6 +24,9 @@ class StatefulDecoder(object):
 
 class StatefulEncoder(object):
     def __init__(self):
+        self.clear()
+        
+    def clear(self):
         self._buffer = b""
         self._buffered_lines: typing.List[Line] = []
 
@@ -33,6 +36,7 @@ class StatefulEncoder(object):
     def push(self, line: Line):
         self._buffer += f"{line.format()}\r\n".encode("utf8")
         self._buffered_lines.append(line)
+        
     def pop(self, byte_count: int):
         sent = self._buffer[:byte_count].count("\n")
         self._buffer = self._buffer[byte_count:]