fix codenarc P2/P3 violations

[coutvv]

I had fixed here all P2 and P3 CodeNarc violations and enable zero tolerance to the new one.

Rules of CodeNarc:
https://codenarc.org/codenarc-rules-formatting.html
https://codenarc.org/codenarc-rules-convention.html

---

Also here I have disabled next CodeNarc rules:

1. UnnecessaryReturnKeyword - because it conflict with other rule ImplicitReturnStatement.
2. SpaceAroundMapEntryColon - resulted code looks so ugly, so I decided to disable this rule. Just look at it:

new File('.').traverse(
                type:FileType.FILES,
                preDir:{ file ->
                    if (file.name == 'target') {
                        return FileVisitResult.SKIP_SUBTREE
                    }
                },
                nameFilter:~/.*\.xsl/,
 )

If you think that I should prefer UnnecessaryReturnKeyword instead of ImplicitReturnStatement rule or if SpaceAroundMapEntryColon should be used - let me know.

[yegor256]

@coutvv excellent contribution, many thanks!