Adding warnings to rules mapping in enum

[orchestr7]

What's done:

1. cosmetic changes in codestyle
2. warnings enum extended
3. small generator and test

[codecov]

Codecov Report

Merging #558 (f99b9dc) into master (205dbfc) will decrease coverage by 0.19%.
The diff coverage is 91.15%.

@@             Coverage Diff              @@
##             master     #558      +/-   ##
============================================
- Coverage     81.88%   81.68%   -0.20%     
  Complexity     1641     1641              
============================================
  Files            78       79       +1     
  Lines          4129     4139      +10     
  Branches       1306     1307       +1     
============================================
  Hits           3381     3381              
- Misses          219      229      +10     
  Partials        529      529              

Flag	Coverage Δ	Complexity Δ
unittests	81.68% <91.15%> (-0.20%)	0.00 <2.00> (ø)

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Impacted Files	Coverage Δ	Complexity Δ
...n/kotlin/org/cqfn/diktat/common/cli/CliArgument.kt	0.00% <ø> (ø)	0.00 <0.00> (ø)
...diktat/ruleset/constants/WarningsTableGenerator.kt	0.00% <0.00%> (ø)	0.00 <0.00> (?)
...tlin/org/cqfn/diktat/ruleset/constants/Warnings.kt	98.31% <100.00%> (ø)	10.00 <2.00> (ø)

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[petertrr]

Really like the mapping table! Shouldn't we add to the README something like to quickly access inspection description, use rules-mapping.md? Or even write this line to the log when diktat is invoked?

[petertrr]

lgtm