Ftr: Support Custom Registry GroupName on Nacos

[ChangedenCZD]

What this PR does:

Which issue(s) this PR fixes:

Fixes #1139

Special notes for your reviewer:

config:

providers:

consumers:

center:

Does this PR introduce a user-facing change?:

通过引用配置中的registry.group或registries[registry].group实现自定义服务GroupName(默认为DEFAULT_GROUP)，与Java一致

[ChangedenCZD]

不应复用service_discovery配置，应与Java一样使用registry.group

[LaurenceLiZhixin]

Pls make your ut pass, tks.

[codecov-commenter]

Codecov Report

Merging #1353 (1184df2) into 3.0 (0aac960) will increase coverage by 0.08%.
The diff coverage is 52.94%.

@@            Coverage Diff             @@
##              3.0    #1353      +/-   ##
==========================================
+ Coverage   41.82%   41.91%   +0.08%     
==========================================
  Files         259      259              
  Lines       15120    15132      +12     
==========================================
+ Hits         6324     6342      +18     
+ Misses       8058     8051       -7     
- Partials      738      739       +1     

Impacted Files	Coverage Δ
registry/nacos/service_discovery.go	1.07% <0.00%> (-0.02%)	⬇️
registry/service_instance.go	0.00% <ø> (ø)
registry/nacos/registry.go	43.84% <40.00%> (-0.51%)	⬇️
registry/nacos/listener.go	79.83% <100.00%> (+0.70%)	⬆️
metadata/report/delegate/delegate_report.go	34.43% <0.00%> (+7.94%)	⬆️

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[ChangedenCZD]

@LaurenceLiZhixin Done.

[zhaoyunxing92]

这个pr可以先缓缓，需要考虑的地方有点多
1.我们之前是interface、group、version确定服务唯一的，如果要添加registry的group修改的地方有多
2.服务上线和下线、监听等等都要有registry的group