Somewhat crude (and a bit lengthy, perhaps) function that returns the size of the text inside a given object (if said object has text).
There does already exist a `GetTextWidth` function (`source/scripting/ScriptFunctions.cpp:L943`). This uses `FontMetrics`. However, `FontMetrics` does not take into account text wrapping, line breaks, new lines, or font changes midway through the text it's fed. (Hence why this does not use a similar approach or, indeed, is in the same file.)
I don't know how useful it is to return `left`, `right`, `top`, or `bottom` values, but they're included for consistency with the returned parameters of the `getComputedSize` function.
As I've said before, I'm something of a newbie when it comes to c++, so if I've done something weird, inefficient, or just plain wrong, tell me gently :grin:
Depends on D836
Written for eventual use with D297, but not (currently) required by it.