Update tmx_converter.py to Python 3

Since I'm not too familiar with Python and especially not with updating
scripts from Python 2 and 3, I did an excersize with AI, trying to get
Claude 3.5 Sonnet to dream up the solution, using aider.

After a little back and forth, resulting in the following 5 commits
(squashed), I think the update looks quite alright and passed the test
(no changes happening in the existing .wlk files).

* fix: Update script to handle Python 3 string and bytes encoding
* fix: Handle bytes-to-string conversion in TMX CSV parsing
* fix: Preserve binary data writing by using direct bytes conversion
* refactor: Remove unnecessary decode() call when splitting CSV buffer
* refactor: Simplify tile conversion by removing unnecessary int() cast

Cost about $0.05 per commit, for a total of $0.22 (and over 100x this in
terms of my own time - it would likely have been quicker and more
educational to not use AI).

0 files changed, 0 insertions, 0 deletions