Bump jetcd vertsion from 0.5.7 to 0.7.7

[aofall]

What is the purpose of the change

1. Bump jetcd vertsion from 0.5.7 to 0.7.7
2. Rename the dubbo-registry-etcd extension name from etcd3 to etcd, because the metadata-etcd and configcenter-etcd use the etcd://127.0.0.1:2379 , the registry address is inconsistent with the other two.

Brief changelog

1. Bump jetcd vertsion from 0.5.7 to 0.7.7
2. Rename the dubbo-registry-etcd extension name from etcd3 to etcd

Verifying this change

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[wcy666103]

why rename etcd3？His name should not be rename easily

[aofall]

why rename etcd3？His name should not be rename easily

You can read What is the purpose of the change again :)

I try to use extend class to compatible the old version now, waiting for CI check pass.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 4 lines in your changes missing coverage. Please review.

Please upload report for BASE (3.0@6b534a8). Learn more about missing BASE report.

Files	Patch %	Lines
...gcenter/support/etcd/EtcdDynamicConfiguration.java	0.00%	3 Missing ⚠️
...o/registry/etcd/EtcdCompatibleRegistryFactory.java	0.00%	1 Missing ⚠️

Additional details and impacted files

@@          Coverage Diff           @@
##             3.0     #398   +/-   ##
======================================
  Coverage       ?   31.35%           
  Complexity     ?      459           
======================================
  Files          ?      150           
  Lines          ?     5205           
  Branches       ?      654           
======================================
  Hits           ?     1632           
  Misses         ?     3400           
  Partials       ?      173           

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