Bump lets-plot to 2.2.1 and 3.1.1

[vlsi]

The update resolves

• Please bundle LICENSE file to the published jar artifacts JetBrains/lets-plot#472
• Is there a way to customize plot background (all the background) in JVM? JetBrains/lets-plot#485

The missing bit is to gather plot theme colors based on Swing colors.

[codecov-commenter]

Codecov Report

Merging #681 (3c1ee5b) into master (0551e4c) will increase coverage by 0.00%.
The diff coverage is n/a.

❗ Current head 3c1ee5b differs from pull request most recent head 4022c1d. Consider uploading reports for the commit 4022c1d to get more accurate results

@@            Coverage Diff            @@
##             master     #681   +/-   ##
=========================================
  Coverage     55.57%   55.58%           
  Complexity    10333    10333           
=========================================
  Files          1059     1059           
  Lines         65055    65051    -4     
  Branches       7403     7399    -4     
=========================================
  Hits          36156    36156           
+ Misses        26350    26346    -4     
  Partials       2549     2549           

Impacted Files	Coverage Δ
...he/jmeter/threads/openmodel/gui/TargetRateChart.kt	6.25% <0.00%> (+0.36%)	⬆️

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