trackbone: add helm option to do a 3 way diff

This is a new option of helm-diff which allows to diff the wanted configuration, the current one (installed manifest) and the installed resources.

Without this the installed resources are not considered in the diff and any manual change on the resources will not be shown in the diff.

As this needs a new version of helm diff and we might have surprises in the generated diff the option is set to false by default.