No onEnterRule when Calva is not auto-indenting

[PEZ]

Don't remove default indentation when formatAsYouType is off. (Calva does this when it is responsible for auto indentation in order to get the cursor to end up at the beginning of the line outside top-level forms.)

Fix #253

I've added a config listener that toggles the onEnterRule off when calva.fmt.formatAsYouType is disabled.

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