[Renderers/termbox] fixed horizontal text culling bug

[Godje]

note to Maintainer

This branch includes the code from PR #523 . If this merges first, the other #523 can be closed.

Bug (before)

Incorrect trimming behavior appears when the text's boundingBox.x coordinate starts going below negative numbers. Instead of culling the text from the left, it trims it from the right.

Visual demonstration of the bug

Before scrolling

After scrolling

Fix (after)

Added a small loop before the main text rendering loop that increments the "text printed counter" (i) without actually printing the text, which then makes the main renderer loop start from the correct character when printing.

Visual demonstration of the fix

Before scrolling

After scrolling

[nicbarker]

Thanks for the great work here!