Fix serial-config.properties for io.helidon.integrations.db:ojdbc and ensure consistent use

[barchetta]

For background see issue #7000, especially the comment from Tomas.

The serial-config.properties for io.helidon.integrations.db:ojdbc is incomplete. Plus we are inconsistent in our use of io.helidon.integrations.db:ojdbc vs com.oracle.database.jdbc:ojdbc8-production and handling of serial-config.properties.

To clean this up we need to:

1. Fix integrations/db/ojdbc/src/main/resources/META-INF/helidon/serial-config.properties so that it contains: pattern=oracle.sql.converter.*;oracle.i18n.text.converter.*
2. Check all examples and archetypes and make sure they depend on io.helidon.integrations.db:ojdbc instead of depending on com.oracle.database.jdbc:ojdbc8-production. Remove serial-config.properties from these examples and archetypes (since it is picked up from the Helidon ojdbc integration).
3. Ensure integration with Oracle DB and proper use of io.helidon.integrations.db:ojdbc and what it provides and possible issues concerning deserialization is documented

[danielkec]

We have already prepared JEP-209 troubleshooting section for serialization filter doc as part of WLS integration documentation:

[danielkec]

Fix didn't make it to 4.x https://github.com/helidon-io/helidon/blob/be27e3007b59f39531ed0c2e48aee4178141b525/integrations/db/ojdbc/src/main/resources/META-INF/helidon/serial-config.properties#L17