Change default editor.soft-wrap.wrap-indicator to empty ""

[aljustiet]

I think that having ↪ to indicate that text is being wrapped takes extra space in the editor.
I also think that as long as there are line numbers by default, a wrapper indicator is not needed.

[sicher]

#14825 moves the indicator to the gutter. I like that change but we'll see if it will be merged. In the meantime it's easy to change the indicator:

[editor.soft-wrap]
wrap-indicator = ""