Create a JDBCFilterToSQL to factor out common needs and issues

All JDBC(ng) related filter to sql have at least two common issues:

• they need to encode geometry literals with the same srid as the properties they are compared against, otherwise the spatial databases will throw an incompatible srid error
• they can leverage the SQLDialect to encode the geometry literals

A common superclass can handle the basic needs, and a prepared statement subclass can deal with the further specialized needs of a PS based dialect.
Or we can have just one class with a configuration parameter, which might help out implementors looking out to have both a PS and a non PS dialect around (for performance issues).