Formula Undo is borked

[Andreya-Autumn]

Load formula.
Change something and apply.
Undo with the editor open.

You get the previous formula back, working correctly. But the editor window has two copies of the code in it, with the second one not applied. Close the editor and reopen and you're fine, but press apply before that and you get an error obviously.

Likely related to #7310

[baconpaul]

void FormulaModulatorEditor::forceRefresh()
{
mainDocument->insertText(0, formulastorage->formulaString);
editor->repaintFrame();
}

That should remove all the text before inserting else the double copy.

main document clear as first line of that fn basically

[baconpaul]

Am on phone otherwise would do obvs. Good catch

[Andreya-Autumn]

->replaceAllContent seems to work fine too. PR coming.