Fix line breaks around IF, ELSE, FI...

[Lotes]

Closes #149

I hope this is the right solution, since these errors were produced because of these table entries in lineBreaksMap. Maybe the standalone-line is too much?

[dhuebner]

@Lotes
The purpose of this map is to validate that some statements need to have a line break before/after/both.

/**
 * [predicate, before, after, both]
 * - predicate: function to filter out a node of interest
 * - before: needs linebreak before
 * - after: needs linebreak after
 * - both: needs linebreak before and after
 */
protected readonly linebreakMap: LinebreakMap = [...]

E.g. PRINT "foo" PRINT "foo" or IF some_object! <> 3 IF some_object! <> 3 should be an error.

See also failing tests.

[dhuebner]

I've added some additional tests and rewrote parts of the validator so we have more control over the lineBreak mask we expect to see around statements. Tests are passing and no of the older one are broken.