Add support for parsing cookie as request items in gateway flow control

[sczyh30]

Signed-off-by: Eric Zhao sczyh16@gmail.com

Describe what this PR does / why we need it

Support parsing cookie as request items in gateway flow control.

Does this pull request fix one issue?

Resolves #813

Describe how you did it

• Add getCookieValue method in RequestItemParser interface and update GatewayParamParser with the logic
• Add cookie parsing logic for Spring Cloud Gateway and Zuul 1.x in respective adapters

Describe how to verify it

Run the test cases.

Special notes for reviews

NONE

[codecov-io]

Codecov Report

Merging #814 into master will increase coverage by 0.04%.
The diff coverage is 47.82%.

@@             Coverage Diff              @@
##             master     #814      +/-   ##
============================================
+ Coverage     41.71%   41.75%   +0.04%     
- Complexity     1376     1379       +3     
============================================
  Files           304      304              
  Lines          8764     8784      +20     
  Branches       1182     1184       +2     
============================================
+ Hits           3656     3668      +12     
- Misses         4662     4669       +7     
- Partials        446      447       +1

Impacted Files	Coverage Δ	Complexity Δ
...dapter/gateway/sc/ServerWebExchangeItemParser.java	45.45% <0%> (-17.05%)	4 <0> (ø)
...adapter/gateway/zuul/RequestContextItemParser.java	8.33% <0%> (-11.67%)	1 <0> (ø)
...dapter/gateway/common/rule/GatewayRuleManager.java	68.37% <100%> (+0.27%)	13 <0> (-1)	⬇️
...apter/gateway/common/param/GatewayParamParser.java	68.57% <71.42%> (+0.31%)	19 <1> (+2)	⬆️
...ava/com/alibaba/csp/sentinel/node/ClusterNode.java	95.23% <0%> (-4.77%)	7% <0%> (-1%)
...a/com/alibaba/csp/sentinel/node/StatisticNode.java	56.17% <0%> (+0.49%)	28% <0%> (+1%)	⬆️
...m/alibaba/csp/sentinel/log/DateFileLogHandler.java	57.57% <0%> (+3.03%)	7% <0%> (+1%)	⬆️
...a/csp/sentinel/slots/statistic/base/LeapArray.java	70.58% <0%> (+3.26%)	34% <0%> (+1%)	⬆️

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[CarpenterLee]

LGTM