Progress: Fix problems regarding zero-width and no-print.

Progress: Fix problems regarding zero-width and no-print.

This is incomplete and more work is needed.

The commit 8f54a1e01d5533e63a38f2849670b20118d18605 was added to bring in `f_utf_is_zero_width_simple()`.

It turns out that I am mis-using zero-width terminology.
The existing `f_utf_is_zero_width()` actually operates as a "no print" rather than a zero-width.

Solve this by renaming the `f_utf_is_zero_width()` to `f_utf_is_print_not()`.
Then rename `f_utf_is_zero_width_simple()` as `f_utf_is_zero_width()`.

The formerly named `f_utf_is_zero_width_simple()` is actually how zero-width is supposed to be.
This brings the code into compliance.