[dex] Fix 'staticClients' env variable usage

[xakraz]

Fixes #36
Relative to dexidp/dex#1664
Requires Dex >= v2.23.0

[xakraz]

"Manually" tested on my deployments.

Makes the transition from:

• id to idEnv
• secret to secretEnv

❓ Maybe some documentation should be added to explain this "opinionated" way ?

[gabibbo97]

Seems ok to me.
Thanks a lot!

About the second point, are you referring to something along the lines of "the splitting of configuration and env variables is because by doing so we can x,y,z" or some other thing?

[xakraz]

@gabibbo97 About the doc, yes exactly.

Especially that the chart's user has still to use the format:

staticClients:
  - id: XXXXX
    secret: YYYY

It will be processed by the template and in the end translated as :

staticClients:
  - idEnv: XXXXX
    secretEnv: YYYY