Add option to remove unwanted features

Add option to remove unwanted features

The odl-karaf-feat-jdbc feature imports all 21 features from
the org.ops4j.pax.jdbc feature.xml file. However, we actually
require only 6 of them: pax-jdbc-spec, pax-jdbc, pax-jdbc-config,
pax-jdbc-h2, pax-jdbc-mariadb and pax-jdbc-pool-dbcp2.

The pax-jdbc-spec, pax-jdbc and pax-jdbc-config have general
usage. The pax-jdbc-h2 is used in AAA. The pax-jdbc-mariadb
and pax-jdbc-pool-dbcp2 is used in TransportPCE project.

The inclusion of unnecessary features not only increases
the weight of the ODL distribution but also introduces
security concerns.

Add an option to the karaf-plugin to remove unwanted features
using Maven property configuration.

JIRA: ODLPARENT-309
Change-Id: I6750b214244d36a39d4086b46a68722adfd9548e
Signed-off-by: Peter Suna <peter.suna@pantheon.tech>
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>