Support reading DecimalArray from JSON data

[nevi-me]

Is your feature request related to a problem or challenge? Please describe what you are trying to do.

The JSON reader doesn't support producing DecimalArray types. I have a TODO: this is incomplete that I left on the reader 2 years ago, which was from when DecimalArray support was incomplete/not implemented.

Describe the solution you'd like

For the JSON reader to be able to produce decimal arrays if specified in the schema.

Describe alternatives you've considered

Coercing decimals to strings or f64, and then casting them after reading. This is inefficient and requires one to programmatically check each field of a schema for JSON fields in order to cast them. Worse as the decimal could be nested inside a list or struct.

Additional context

Systems have some freedom when producing JSON data. For example, Debezium has 3 modes for handling decimals [0], where decimals can either be binary, strings or floats. I also vaguely remember some system/process writing the data as bytes.
It would be useful for us to be able to handle at least the modes supported by Debezium.

[0] https://debezium.io/documentation/reference/stable/connectors/sqlserver.html#sqlserver-property-decimal-handling-mode

[tustvold]

#2580 is possibly related / could share some logic