String module outputs are crammed into a single line and can be unreadable

[ctrueden]

The bundled Example_Script.js produces a multi-line string output, intended for display in a text area. But napari-imagej puts it into a single line text field, and squelches the newlines, and grays out the content with no scroll bar, making it unreadable in full. This might be a place where we need to add multi-line text area support to magic_gui?

[gselzer]

If it's an output, then we are creating that widget by ourselves (here) - we can simply update the widget that is returned.