Add throttle limit distribution

[kirillov6]

Added throttle limit distribution.

Fixes #586

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 90.72398% with 41 lines in your changes are missing coverage. Please review.

Project coverage is 71.36%. Comparing base (67ecc39) to head (5534009). Report is 11 commits behind head on master.

:exclamation: Current head 5534009 differs from pull request most recent head 9a4885e

Please upload reports for the commit 9a4885e to get more accurate results.

Files	Patch %	Lines
plugin/action/throttle/buckets.go	82.20%	20 Missing and 1 partial :warning:
plugin/action/throttle/redis_limiter.go	91.66%	6 Missing and 3 partials :warning:
plugin/action/throttle/throttle.go	86.66%	4 Missing and 2 partials :warning:
plugin/action/throttle/in_memory_limiter.go	94.11%	4 Missing and 1 partial :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #587      +/-   ##
==========================================
+ Coverage   70.83%   71.36%   +0.52%     
==========================================
  Files         124      126       +2     
  Lines       12572    12854     +282     
==========================================
+ Hits         8906     9173     +267     
- Misses       3150     3156       +6     
- Partials      516      525       +9     

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