Font(?) issue on Fedora 38 and CentOS Stream 9

[jpagliaccio]

Getting this (maybe) font issue on Fedora and Stream 9. bCNC version 0.9.15.
FYI, it looks like Helvetica is not in the repos any longer. Please let me know how I can help and test.

And the code is working, and it even shows the down arrow font/icon when expanded.

Thanks for writing bCNC.

[jpagliaccio]

I made the following changes in Unicode.py to have characters show up.

BLACK_RIGHT_POINTING_TRIANGLE = "\u2500" # changed from \u25B6, horz line
BLACK_DOWN_POINTING_TRIANGLE = "\u25BC" # not changed, \u25BC always worked

BALLOT_BOX = "\u2591" # changed from \u2610, to light shade
BALLOT_BOX_WITH_X = "\u221A" # changed from \u2612, to square root