coding style

[dfang]

1. about filename convention when generating

when running goctl api new or goctl rpc new, you can specify -style to generate with go_zero naming style(greet_handler.go, greet_logic.go, service_context.go). the default value of -style should be go_zero. if the goal is be consistent and simplify code, just remove other options.

golang/go#36060 (comment)

2. add golangci-lint to Github Actions

Currenty in .github/workflows/go.yml, there is only gofumpt in Lint section. but gofumt is just a stricter gofmt, maybe we can add golangci-lint to the workflow