support bind uri param

[thinkerou]

ref #846

for example:

type Uri struct {
  A string `uri:"name" binding:"required"`
  B float32 `uri:"total" binding:"required"`
  C int `uri:"age" binding:"required"`
}

func() {
  r := gin.Default()
  r.GET("/rest/n/:name/:total/:age/*other", func(c *gin.Context) {
    var uri Uri
    if err:= c.ShouldBindUri(&uri); err != nil {
      c.JSON(400, gin.H{"msg": err})
      return
    }
    ...
  }
}

Now you could use c.ShouldBindUri instead of c.Param

[codecov]

Codecov Report

Merging #1612 into master will increase coverage by 0.1%.
The diff coverage is 100%.

@@            Coverage Diff            @@
##           master    #1612     +/-   ##
=========================================
+ Coverage   99.29%   99.39%   +0.1%     
=========================================
  Files          40       41      +1     
  Lines        1973     1988     +15     
=========================================
+ Hits         1959     1976     +17     
+ Misses         10        9      -1     
+ Partials        4        3      -1

Impacted Files	Coverage Δ
binding/binding.go	100% <ø> (ø)	⬆️
binding/uri.go	100% <100%> (ø)
binding/form_mapping.go	100% <100%> (+1.45%)	⬆️
context.go	99.5% <100%> (ø)	⬆️

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[thinkerou]

@appleboy @javierprovecho please help review the feature, thanks!

[martin-dos-santos]

Any news on this? Will be great to have this feature.