We add a 'temporary' option to line breakpionts and try and clear any
temporary breakpionts on the line we end up stopping on. This might not
be art, but _probably_ works in almost all cases that matter.
it's a bit hacky the way we have to push the reason around, but we don't
know where we stopped until we actually get the stack trace response and
SetCurrentFrame
Move temporary breakpionts to match server response
Also delete any existing ones when adding a new one and add tests for
run-to-cursor.
Only continue after we successfully set the breakpoints. This makes it
work in go
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