Use json.Number when scan to JSONMap

[levanlongktmt]

• [x] Do only one thing
• [x] Non breaking API changes
• [x] Tested

What did this pull request do?

Use json.Decoder.UseNumber() when Scan []byte to JSONMap

User Case Description

When scanning JSONMap (a.k.a map[string]interface{}) from []byte, it returns the incorrect value of int64 and uint64 if the value is more than 18 digits. The reason is by default json.Unmarshal treat int64 and uint64 as float64 and loses the numeric precision. For example

content := `{"user_id": 1085238870184050699, "name": "Name of user"}`
obj := make(datatypes.JSONMap)
obj.Scan([]byte(content))
fmt.Print(obj["user_id"])
// before: obj["user_id"] = 1.0852388701840507e+18 <-- incorrect value
// after: obj["user_id"] = 1085238870184050699 <-- correct value
fmt.Print(cast.ToInt64(obj["user_id"])) // use github.com/spf13/cast
// before: obj["user_id"] = 1085238870184050688 <-- incorrect value
// after: obj["user_id"] = 1085238870184050699 <-- correct value