[WIP]: add dubbo-go cli and edit readme

[cjphaha]

Move dubbogo-cli to the dubbogo-cli directory and modify the readme document. Refer https://github.com/apache/dubbo-go/issues/1799

[AlexStocks]

pls fix the ci failure

[codecov-commenter]

Codecov Report

Merging #1971 (df3c99f) into 3.0 (9d88f31) will increase coverage by 0.14%. The diff coverage is 0.00%.

@@            Coverage Diff             @@
##              3.0    #1971      +/-   ##
==========================================
+ Coverage   44.54%   44.69%   +0.14%     
==========================================
  Files         283      283              
  Lines       17069    17106      +37     
==========================================
+ Hits         7603     7645      +42     
+ Misses       8663     8653      -10     
- Partials      803      808       +5     

Impacted Files	Coverage Δ
config/consumer_config.go	22.58% <0.00%> (ø)
config/provider_config.go	41.53% <0.00%> (ø)
protocol/dubbo3/dubbo3_protocol.go	54.54% <0.00%> (ø)
config/graceful_shutdown_config.go	89.83% <0.00%> (-2.90%)	:arrow_down:
config/logger_config.go	63.33% <0.00%> (+0.62%)	:arrow_up:
metadata/definition/definition.go	70.66% <0.00%> (+7.87%)	:arrow_up:
metadata/report/delegate/delegate_report.go	35.09% <0.00%> (+8.60%)	:arrow_up:

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