diktat-examples refactoring and CI

[petertrr]

This pull request closes #517

• Examples are corrected, they now use diktat plugins with correct versions
• All versions are updated from release.yml
• Functional tests run against exmples

[codecov]

Codecov Report

Merging #548 (83f8df8) into master (718c678) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master     #548   +/-   ##
=========================================
  Coverage     81.93%   81.93%           
  Complexity     1637     1637           
=========================================
  Files            78       78           
  Lines          4123     4123           
  Branches       1302     1302           
=========================================
  Hits           3378     3378           
  Misses          219      219           
  Partials        526      526           

Flag	Coverage Δ	Complexity Δ
unittests	81.93% <ø> (ø)	0.00 <ø> (ø)

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[orchestr7]

lgtm

[orchestr7]

btw - do we keep examples like a separate project, not a sub-module?

[petertrr]

btw - do we keep examples like a separate project, not a sub-module?

yes, it's just a folder