Also fixes a bug where we didn't triangulate at all when the char
count didn't warrant the likely overhead of spinning up a
thread_pool.
And fix another bug where EDA_TEXT::GetRenderCache() wasn't using
the given font.
Also reverts using the cache for drawing-sheet text. The text
items are created from scratch from the data items each time
they're drawn, so there's never an existing cache to make use of.
Instead, we now check that the item is in the view, using a very
approximate bounding box generator (because even generating a
real bounding box shows up large in profiles).
And, lastly, fixes a bug where EndPos was never considered in
DS_DATA_ITEM::IsInsidePage().
Fixes https://gitlab.com/kicad/code/kicad/-/issues/14822
f35a88ce0b