重构util接口，支持按照key查找json，并转换vector list

cheliequan

2023-01-13 946823215bac2c859df843f7b01636f5fda34ed4

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new_obj.to_string()=[1.20,3.40,123456.78,5.00,23000000000.00]
new_obj.to_string()=[1.2,3.4,123456.78,5.0,2.3e10]