Mod:refactor to add base_registry

[hxmhlt]

What this PR does:

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

[codecov-io]

Codecov Report

Merging #348 into develop will decrease coverage by 0.5%.
The diff coverage is 89.85%.

@@             Coverage Diff             @@
##           develop     #348      +/-   ##
===========================================
- Coverage    67.65%   67.14%   -0.51%     
===========================================
  Files          123      145      +22     
  Lines         7317     7692     +375     
===========================================
+ Hits          4950     5165     +215     
- Misses        1894     2037     +143     
- Partials       473      490      +17

Impacted Files	Coverage Δ
config/consumer_config.go	51.92% <ø> (-4.22%)	⬇️
config_center/zookeeper/impl.go	40% <ø> (ø)	⬆️
remoting/zookeeper/listener.go	52.02% <ø> (ø)	⬆️
registry/zookeeper/listener.go	60.86% <ø> (ø)	⬆️
config/provider_config.go	52.77% <ø> (-5.76%)	⬇️
registry/etcdv3/listener.go	76.74% <ø> (ø)	⬆️
config/base_config.go	63.95% <ø> (ø)	⬆️
config/metric_config.go	0% <0%> (ø)
remoting/zookeeper/client.go	68.06% <100%> (ø)	⬆️
metrics/prometheus/reporter.go	100% <100%> (ø)
... and 30 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update af4683c...0703ced. Read the comment docs.

[flycash]

Did you test it end to end? Or run the samples?

[pantianying]

Can you remove the recursive logic from the zookeeper registry center in this PR，distinguish from configuration center😛😘

[hxmhlt]

Did you test it end to end? Or run the samples?

Yes，I run it in dubbo-samples

[hxmhlt]

Can you remove the recursive logic from the zookeeper registry center in this PR，distinguish from configuration center😛😘

I think it will be another pr. We need to create a new pull request to do that.

[pantianying]

LGTM

[zouyx]

LGTM, but need some comment for registry/base_registry.go

[fangyincheng]

LGTM

[AlexStocks]

LGTM