Allow a user to select which metric(s) they would like CMEW to run

- Metrics are listed in `rose-suite.conf` file, True or False
- Code exists somewhere (in a separate file) that creates two lists based on whether the metric is AutoAssess or ESMValTool
- Two lists are defined under [[task parameters]](https://github.com/MetOffice/CMEW/blob/main/climate-model-evaluation-workflow/flow.cylc#L9)
- Different graphs (and tasks) are defined based on whether the metric is AutoAssess or ESMValTool
- Process tasks for AutoAssess and ESMValTool can be provided via optional application configuration, see [Rose documentation: Application Configuration](http://metomi.github.io/rose/doc/html/api/configuration/application.html)
- Ideally, the outcome of this work will enable a scientist to easily update CMEW after they have converted their AutoAssess metric to ESMValTool, i.e. moving the assessment area from an "AutoAssess" list to an "ESMValTool" one

Start by tracing the metric flags in rose-suite.conf into the metric lists and task parameters in flow.cylc. Review the Rose application configuration used for AutoAssess and ESMValTool process tasks. Done should let a scientist select metrics and move a converted metric between the two groups without editing workflow logic.

Written by the indexing model from the issue text.