Draft: Helm chart

following discussion with @swinbank and @ghughes1066 I can provide the helm chart I used to deploy ESAP in CSCS.

edit: I do not know what you prefer, should I make an issue first? How do I mark when it's ready for review? Is it sufficient to remove the Draft status? Right now it's a real chart, but I would need to tidy it up, replace docker image references, etc. So I need to do that before asking for someone to look in. For now I mostly just wanted to check that I can create an MR.