Move creating new annotation version into management command

[davmlaw]

Currently, we do a get_or_create in here annotation.annotation_versions.get_variant_annotation_version which is triggered by visiting annotation pages

Better to do in management command and/or deployment tool

[davmlaw]

Made it check vs VEP current - but this blew annotation page out to ~20 seconds

I split up the annotation page per genome build so now it can at least do things in parallel

User testing

The main point of this is to not accidentally trigger an unexpected annotation version upgrade if the underlying VEP and latest DB variant annotaiton version get out of sync - which requires a bit of deployment config to see

But should test that annotation page works as before