Add QueryEscape to general funcmap (#17526)

QueryEscape was only added to the text funcmap. Add this to the main template funcmap
too.

Signed-off-by: Andrew Thornton <art27@cantab.net>

modules/templates/helper.go

@@ -379,6 +379,7 @@ func NewFuncMap() []template.FuncMap {
 		"MermaidMaxSourceCharacters": func() int {
 			return setting.MermaidMaxSourceCharacters
 		},
+		"QueryEscape": url.QueryEscape,
 	}}
 }