GIN & GORM logging integration

[applejag]

Summary

Adds easy integration for Gin-Gonic & GORM with wharf-core's logging. See the _example_test.go files for how they're meant to be used, but here's the gist:

// Gin-Gonic
r := gin.New()

r.Use(ginutil.DefaultLoggerHandler)
gin.DefaultWriter = ginutil.DefaultLoggerWriter
gin.DefaultErrorWriter = ginutil.DefaultLoggerWriter

// GORM
db, err := gorm.Open(postgres.Open("host=localhost"), &gorm.Config{
	DryRun:               true,
	DisableAutomaticPing: true,
	Logger: gormutil.NewLogger(gormutil.LoggerConfig{
		Logger: logger.NewScoped("GORM"),
	}),
})

Motivation

GORM and Gin still has their built-in ways for logging, but allow you to add your own logger if you want to. These changes makes that integration easy, so with just a few lines then both GORM and Gin will use wharf-core/pkg/logger for logging instead of their own solutions, which will bring a more unified visual to our logs

[Alexamakans]

Looks good to me, just a few typos and nits.

[fredx30]

Code style seems fine to me.

Th PR description is missing both what and why. What problem does this solve? What does the integration do?

[applejag]

Code style seems fine to me.

Th PR description is missing both what and why. What problem does this solve? What does the integration do?

Updated desc