Use configLocation value

[katlim-br]

Many lines of the charts refer to the /quickwit/node.yaml hardcoded path.

However, I think they should refer to the configLocation variable.

BEFORE:
Example

        volumeMounts:
          - name: config
            mountPath: /quickwit/node.yaml

FIXED:

        volumeMounts:
          - name: config
            mountPath: {{ $.Values.configLocation }}

(For the subPath field, it could be replaced to be dynamic and use the Helm function "base")

[katlim-br]

added this PR, and tested it locally #116

[fulmicoton]

@rdettai can you have a look?