Add support for customizing the JsonType underlying Oracle column type

[vladmihalcea]

When using Oracle, there are three ways to store JSON objects:

• using the 21c JSON column type
• using a VARCHAR2 column
• using a BLOB or CLOB column

Traditionally, the JsonType assumed the VARCHAR2 column is used, but now you can customize the default column type, like this:

properties.setProperty(
	Configuration.PropertyKey.DEFAULT_JSON_TYPE.getKey(),
	"blob"
);

or

properties.setProperty(
	Configuration.PropertyKey.DEFAULT_JSON_TYPE.getKey(),
	"varchar"
);

or

properties.setProperty(
	Configuration.PropertyKey.DEFAULT_JSON_TYPE.getKey(),
	"json"
);