Change (de)serialization formats

[vyacheslav-pushkin]

Support for big numbers

Currently long and BigDecimal values are serialized as numbers. A JavaScript number is an IEEE 754 64-bit double-precision floating-point format number, which is not enough to safely represent a sufficiently large long or a sufficiently large and/or precise BigDecimal.

For example, an attempt to store Long.MAX_VALUE (9,223,372,036,854,775,807) in a number will result in 9,223,372,036,854,776,000 (maximum value that can be safely represented as a number is 9,007,199,254,740,991).

We might prefer to serialize long and BigDecimal values as strings instead.

Datatype-independent serialization

Currently serialization format depends on datatype. It means that change in datatype format has to be replicated on client side. It might be better if REST API would use standard datatype-agnostic formats for data transfer.

Support for offsets

(Related to cuba-platform/frontend#91)

Currently offset is only supported for OffsetDateTime and OffsetTime. Other temporal types implicitly have server's offset. The server's offset is not known on client side. This may lead to wrong values being displayed/saved if server and client have different offsets.

dateAttr: "2019-11-07",
timeAttr: "20:16:02",
dateTimeAttr: "2019-11-07 20:16:02.613",
localDateAttr: "2019-11-07",
localTimeAttr: "20:16:02",
localDateTimeAttr: "2019-11-07 20:16:02.613",

offsetDateTimeAttr: "2019-11-07 20:16:02.613 +0400",
offsetTimeAttr: "20:16:02 +0400"