No tests for mapper Date

[ArtDu]

Create a test that shows the mapping behavior of the Date data type from java to tarantool. What type of data is the conversion expected to be? (Number by my testing)

@Schema(description = "Some date")
private Date date;

And this look strange: https://github.com/tarantool/cartridge-springdata/blob/ed7e3b4d712476b32df223cd6f8df7111208c370/src/main/java/org/springframework/data/tarantool/core/convert/DateConverters.java#L28-L29

It is also necessary to discuss why some converters are in cartridge-java, and some must be related to spring converters. This is necessary in order to understand which pipeline the date passes from spring to tarantool, or from carg-java to tarantool.