Fix 382 and 389

[TobiasJacob]

Fix #382

• Add a way to set the priority class. Helpful to prevent eviction of timescaledb in case of memory pressure.

Fix #389

• The default values made setting up Azure backups after deployment complicated.
• Added an example (with fake credentials) to give people an understanding of how to enable Azure backups.

[CLAassistant]

All committers have signed the CLA.

[paulfantom]

Sorry for slow reply, I left few comments.

[gunnarsundberg]

Hello @TobiasJacob I submitted a PR for adding GCS backups (#401), but our methods are slightly different. Perhaps we should coordinate an effort to enable and document both Azure and GCP backups in a way that's consistent? Or, if you'd like, you could make this PR focus on priority class and I can add Azure to my PR :)

[TobiasJacob]

Hello @gunnarsundberg, yes I see, the configuration of Azure through secrets is probably a better approach. I think you have a better understanding of how to implement that, if you have a way to try out Azure it's probably better if you go ahead an implement it. I can create a new PR for the priority class part.

[FaunoBarberini]

this should be string, and there should be no "minimum"