Cleanup unused configs and stale code

[rtisma]

After briefly looking at the application.yml (config file) for ego, some configs were found to be stale/not-used anywhere in the code.

For example jwt.secret https://github.com/overture-stack/ego/blob/3.0.0/src/main/resources/application.yml#L4-L5

There are probably alot more, that are not needed, and its should be cleaned up, becuase it was confusing while updating a the helm chart for ego.

[rosibaj]

@andricDu is this still valid?