Release version 4 compatible xtdb connector

[planetf1]

Now that Egeria 4 has shipped, we should ship a v4 compatible xtdb connector release

• XTDB connector is not publishing the jar-with-dependencies #466 has some minor tidyups (I can do)
• there are other functional issues reported, Error locating module #470 & Getting OMRS-XTDB-REPOSITORY-500-003 on config #469 could relate to version/packaging concerns & need checking
• there may be other issues to consider

@cmgrote @mandy-chessell @dwolfson

[planetf1]

Have been working on release
@mandy-chessell should be ready for the final steps now

• release on oss.sonatype.org
• creating the github release

[planetf1]

The 4.1 connector was shipped, so closing