Include Oracle dialect in webservice and cleanup documentation for GeoRaster

[stephanr]

The oracle JDBC driver is currently available through maven central with a License [1] that allows redistribution.
In my opinion, there are no more blocking topics which prevent us from including the Oracle SQL-dialect and the JDBC driver in the regular web-service build.

If the TMC agrees to include oracle as a database for the regular web-service builds, the following tasks have to be completed.

• Update documentation, that only proprietary drivers are required for Oracle GeoRaster
• Update maven configuration to include the Oracle sqldialect and its required dependencies.

[1] Oracle Free Use Terms and Conditions (FUTC)

• https://www.oracle.com/downloads/licenses/oracle-free-license.html