<!-- Keep the title short & concise so anyone non-technical can
understand it,
the title appears in PTB changelogs -->
#### Brief overview of PR changes/additions
Pass TMxpContext by reference to tagHandled() instead of storing it as a
member pointer via initialize(). Null out zlib stream pointers after use
in decompressBuffer().
#### Motivation for adding to Mudlet
Resolve CodeQL warnings about a potential issue.
#### Other info (issues closed, discussion etc)
#### Brief overview of PR changes/additions
Fixes MXP support for MUDs that require additional handshaking, and
prevents MXP comments and status tags from appearing as raw text.
#### Motivation for adding to Mudlet
Some MUDs (like Discworld) send extra MXP signals that Mudlet wasn't
handling, causing MXP features like clickable links to not work.
Additionally, MXP comments and status bar tags were being displayed as
raw text instead of being handled properly.
#### Other info (issues closed, discussion etc)
Fixes#8908
---
Before:
<img width="805" height="524" alt="Screenshot 2026-02-06 at 10 10 37 PM"
src="https://github.com/user-attachments/assets/90833481-d6f1-4b3f-bc2a-6f9d1d0cc017"
/>
After:
<img width="798" height="892" alt="Screenshot 2026-02-06 at 10 39 29 PM"
src="https://github.com/user-attachments/assets/b24b8ede-4e1d-4bb9-b55b-ff11ace27d67"
/>
