upgrade a chart

[fcomte]

We can upgrade a chart.

There are two steps involved :

• [ ] First is to saved the query string ( as we do for a saved config inside vault ) inside a specific values of the helm chart. onyxia.userDefinedValues.
• [ ] In a second step we can create a button and linked it to the upgrade/install api calls.

For that we need to save the fixed values somewhere (maybe in a custom values). Onyxia-web must fill all the automatic values then fixed values are apply ( fixed values overwrite automatic values )