- Extract private `deparenthesizeOnce` and repeat it until get the same expression
- Drop redundant parameter `deparenthesizeRecursively`
- Drop some usages of `safeDeparenthesize` in `deparenthesize`
because even if `deparenthesize` returns null (i.e. something was not parsed)
there is no sense in working with such expressions
Note, that `deparenthesize` now unwraps nested labels' declaration (see changes in testData),
but it seems to be reasonable
Dmitry Petrov