[ISSUE #3852]Move the Logappender module to external

[duhenglucky]

What is the purpose of the change

Based on the discussion and vote result of separate logappender repo, move logappender the to rocketmq-external repo.

Brief changelog

XX

Verifying this change

XXXX

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[coveralls]

Coverage decreased (-0.006%) to 51.355% when pulling fa62032 on duhenglucky:logappender into 48e8c19 on apache:develop.

[codecov-commenter]

Codecov Report

Merging #3851 (fa62032) into develop (48e8c19) will decrease coverage by 0.07%.
The diff coverage is n/a.

@@              Coverage Diff              @@
##             develop    #3851      +/-   ##
=============================================
- Coverage      47.37%   47.29%   -0.08%     
+ Complexity      4916     4873      -43     
=============================================
  Files            636      632       -4     
  Lines          42481    42276     -205     
  Branches        5561     5544      -17     
=============================================
- Hits           20124    19996     -128     
+ Misses         19856    19784      -72     
+ Partials        2501     2496       -5     

Impacted Files	Coverage Δ
...org/apache/rocketmq/common/stats/StatsItemSet.java	41.79% <0.00%> (-8.96%)	⬇️
...he/rocketmq/client/trace/AsyncTraceDispatcher.java	78.21% <0.00%> (-2.98%)	⬇️
...lient/impl/consumer/DefaultMQPushConsumerImpl.java	40.17% <0.00%> (-2.29%)	⬇️
...a/org/apache/rocketmq/filter/util/BloomFilter.java	59.13% <0.00%> (-2.16%)	⬇️
...mq/client/impl/consumer/RebalanceLitePullImpl.java	72.05% <0.00%> (-1.48%)	⬇️
...etmq/client/latency/LatencyFaultToleranceImpl.java	50.00% <0.00%> (-1.29%)	⬇️
...rocketmq/client/impl/factory/MQClientInstance.java	50.07% <0.00%> (-1.22%)	⬇️
...e/rocketmq/client/impl/consumer/RebalanceImpl.java	43.75% <0.00%> (-0.79%)	⬇️
...nt/impl/consumer/ConsumeMessageOrderlyService.java	49.82% <0.00%> (-0.72%)	⬇️
...a/org/apache/rocketmq/store/StoreStatsService.java	29.31% <0.00%> (-0.66%)	⬇️
... and 8 more

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