Output trigger type data to InfluxDB

Description

This is a backwards compatible change to add trigger-type output data to Influx, eg data of the form:

{
    "time": time_val,
    "fields": {
        "data_field1": data_val1,
        "data_field2": data_val2,
        "data_field3": data_val3,
        ...
     }
}

This will make it possible to add a float FAR value as metadata to every measurement. This way, we can more naturally threshold on different FAR values rather than the current scheme which uses tags for the FAR and constrains the possible values to a small set of strings. With this structure it will be much easier to add an arbitrary number of numeric metadata fields.

For now, the change is backwards compatible, ie all the same time-series data is still output. This way the old Grafana dashboards should still work. But this may be removed in a future version.

To-do:

• test code changes on fake-data scheme
• test code changes on real data
• update grafana dashboard template(s) at https://git.ligo.org/rebecca.ewing/test-suite/-/tree/main/web