[errors] Add errortypes for detect and create common error

[at15]

The errors/errortype(s) is already created but has no working code in it

Goals

• provide IsXX helper for common built in errors
• interface for common application errors
  • and helper to create them without define new struct in app code
• (optional) error collecting interface
  • need to do more survey, especially on distributed tracing

[codecov[bot]]

Codecov Report

Merging #106 into master will increase coverage by 4.44%. The diff coverage is 79.55%.

@@            Coverage Diff             @@
##           master     #106      +/-   ##
==========================================
+ Coverage   47.91%   52.35%   +4.44%     
==========================================
  Files          54       59       +5     
  Lines        2016     2183     +167     
==========================================
+ Hits          966     1143     +177     
+ Misses        961      952       -9     
+ Partials       89       88       -1

Impacted Files	Coverage Δ
errors/cause.go	77.27% <ø> (+18.18%)	:arrow_up:
errors/errortype/http.go	0% <0%> (ø)
errors/multi.go	83.15% <100%> (+29.31%)	:arrow_up:
util/httputil/http.go	9.67% <100%> (+9.67%)	:arrow_up:
log/logx/http.go	100% <100%> (ø)
log/logger_identity.go	68.42% <100%> (ø)	:arrow_up:
util/httputil/writer.go	33.33% <33.33%> (+33.33%)	:arrow_up:
log/handler.go	66% <50%> (+1.29%)	:arrow_up:
errors/errortype/common.go	78.57% <78.57%> (ø)
errors/errortype/std.go	82.5% <81.57%> (ø)
... and 11 more

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