[PostgreSQL] Add DeserializationConverterFactory for PostGIS schemas

[Elephantusparvus]

This adds a simple DeserializationConverterFactory for PostgisGeometry objects, like it is done in with the com.ververica.cdc.connectors.mysql.table.MySqlDeserializationConverterFactory. But in the case of PostGIS the data is encoded in ewkb, which should already include the srid (see here https://github.com/debezium/debezium/blob/main/debezium-connector-postgres/src/main/java/io/debezium/connector/postgresql/PostgresValueConverter.java and https://github.com/debezium/debezium/blob/main/debezium-connector-postgres/src/main/java/io/debezium/connector/postgresql/PostgisGeometry.java), thus converting it to GeoJSON would be an In the string case this converter returns an hex encoded string of the ewkb, which could be directly transformed to a corresponding geometry type column of apache sedona (https://sedona.apache.org/tutorial/flink/sql/) with the 'ST_GeomFromWKB' function. In the byte case the raw ewkb byte array is directly returned. This array again can easily be converted into the corresponding geometry object e.g. by using https://locationtech.github.io/jts/javadoc/org/locationtech/jts/io/WKBReader.html#read-byte:A-.

[yuxiqian]

Hi @Elephantusparvus, thanks for your contribution! Seems this issue has been addressed by #1554, would you mind if I close this PR?