Ctcp fixes

[theunkn0wn1]

This pull request adjusts several issues found in the CTCP handling library, which prevented proper handling of ctcp messages.

Validation test:

>unknown[pydle]< CTCP HI
>unknown[pydle]< CTCP HI fo
* unknown[pydle] has quit (Read error)
* unknown[pydle] (~unknownpy@674CBF4E.74FC38EB.24F6D0A2.IP) has joined
>unknown[pydle]< CTCP HI fo
* Received a CTCP HI fo from unknown[pydle]
>unknown[pydle]< CTCP HI fo fo
* Received a CTCP HI fo fo from unknown[pydle]
>unknown[pydle]< CTCP VERSION
-unknown[pydle]- VERSION pydle v0.9.1

relevent ctcp callback:

    async def on_ctcp(self, by, target, what, contents):
        print(f"on_ctcp invoked with by='{by}'\ttarget='{target}'\twhat='{what}'\tcontents = {contents}")
        await self.ctcp(by, what, contents=contents)