Git for vm

[james-bruten-mo]

Changes required to install UM dependencies (shumlib and gcom) post the UM git migration.
The change is primarily adding the code to parse a github url string and clone from there.
The option to checkout from fcm is left there. I've also left the setup of the fcm offline keywords as this might still be useful until mosrs has been removed? Happy to change that if that's preferred.

The two sources (gcom and shumlib) use ssh access for now as they are both private repos, so this will require an ssh key being setup first. I'll need to update the UM VM doc paper to note this.

[theabro]

The usr/local/bin/install-rose-meta and usr/local/bin/install-um-data file still references the MOSRS pages, and so equivalents for Git will need to be included.

The full set of files within the repo that mention code.metoffice.gov.uk are:

opt/metomi-site/etc/fcm/keyword.cfg
opt/metomi-site/etc/rose.conf.redhat
opt/metomi-site/etc/rose.conf
opt/metomi-site/etc/rose/rose.conf
usr/local/bin/install-rose-meta
usr/local/bin/install-um-data
usr/local/bin/mosrs-cache-password
usr/local/bin/mosrs-setup-gpg-agent
usr/local/bin/um-setup

Within the usr/local/bin/um-setup file there are numerous create_keyword lines that also point to MOSRS - do these also need to be changed? We'll also need to consider the possibility of someone wanting to make an e.g. UM13.9 VM still, or explicitly state that this is no longer supported (and then remove all reference to MOSRS from this repo).

UKCA data is taken currently from our JASMIN GWS, so that might be an alternative but is much more prone to disruption than somewhere else. Perhaps Zenodo?

Of course, some things like Rose suites are still on MOSRS for the moment, and we can keep the UM data there for a bit longer too.