Service discovery

[flycash]

What this PR does:

The necessary interface definition of align with dubbo2.7.5

[codecov-io]

Codecov Report

❗ No coverage uploaded for pull request base (feature/dubbo-2.7.5@5ce2598). Click here to learn what that means.
The diff coverage is 64.48%.

@@                  Coverage Diff                   @@
##             feature/dubbo-2.7.5     #385   +/-   ##
======================================================
  Coverage                       ?   66.72%           
======================================================
  Files                          ?      150           
  Lines                          ?     7963           
  Branches                       ?        0           
======================================================
  Hits                           ?     5313           
  Misses                         ?     2146           
  Partials                       ?      504

Impacted Files	Coverage Δ
filter/filter_impl/auth/sign_util.go	69.23% <ø> (ø)
filter/filter_impl/auth/provider_auth.go	52.94% <ø> (ø)
filter/filter_impl/auth/default_authenticator.go	80% <ø> (ø)
filter/filter_impl/auth/accesskey_storage.go	100% <ø> (ø)
filter/filter_impl/auth/consumer_sign.go	60% <ø> (ø)
protocol/dubbo/client.go	68.75% <0%> (ø)
remoting/zookeeper/listener.go	52.57% <100%> (ø)
config_center/nacos/factory.go	12.5% <12.5%> (ø)
config_center/nacos/client.go	57.26% <57.26%> (ø)
config_center/nacos/facade.go	64.7% <64.7%> (ø)
... and 4 more

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