Deploy QFieldCloud on a separate server - self hosted via helm chart

[spwoodcock]

• app.qfield.cloud does not allow user management.
• If we deployed our own instance, the whole QField management flow would work as we expect.
• There is a community helm chart: https://github.com/opengisch/QFieldCloud-helm-chart
• Probably needs a little polish up, then deploying in our infra so we can use it with FieldTM.
• It does add a little maintenance burden to us, but not a huge one.

[linear]

TECH-1073