New rule for complex expression

[kentr0w]

What's done:

Created new rule

Which rule and warnings did you add?

This pull request closes

Actions checklist

• Implemented Rule, added Warnings
• Added tests on checks
• Updated diktat-analysis.yml
• Updated available-rules.md

closes #676
closes #241

[codecov]

Codecov Report

Merging #680 (d425513) into master (d34ed1c) will increase coverage by 0.07%.
The diff coverage is 78.12%.

@@             Coverage Diff              @@
##             master     #680      +/-   ##
============================================
+ Coverage     80.00%   80.08%   +0.07%     
- Complexity     1864     1871       +7     
============================================
  Files            88       88              
  Lines          4852     4870      +18     
  Branches       1560     1565       +5     
============================================
+ Hits           3882     3900      +18     
+ Misses          241      238       -3     
- Partials        729      732       +3     

Flag	Coverage Δ	Complexity Δ
unittests	80.08% <78.12%> (+0.07%)	0.00 <17.00> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ	Complexity Δ
...at-rules/src/main/kotlin/generated/WarningNames.kt	0.00% <ø> (ø)	0.00 <0.00> (ø)
.../org/cqfn/diktat/ruleset/rules/NullableTypeRule.kt	80.26% <50.00%> (-0.56%)	39.00 <7.00> (ø)
...cqfn/diktat/ruleset/rules/AnnotationNewLineRule.kt	87.50% <66.66%> (+1.13%)	14.00 <0.00> (ø)
...lin/org/cqfn/diktat/ruleset/rules/SmartCastRule.kt	64.46% <66.66%> (+0.29%)	36.00 <0.00> (ø)
...rg/cqfn/diktat/ruleset/rules/files/NewlinesRule.kt	81.70% <85.71%> (+1.34%)	129.00 <10.00> (+7.00)
...tlin/org/cqfn/diktat/ruleset/constants/Warnings.kt	97.69% <100.00%> (+0.01%)	11.00 <0.00> (ø)

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[petertrr]

Please check snapshot diktat check, there are a lot of new error there.

[petertrr]

LGTM

[aktsay6]

lgtm