SWATCH-2306: Create grafana dashboard for PAYG metrics (#4158)

Jira issue: SWATCH-2306

## Description
The metrics to use for each are:
- Metered, which is the first "phase". It's
swatch_metrics_ingested_usage_total: Added by SWATCH-2297
- Tallied, which is the second one: It's
swatch_tally_tallied_usage_total: Added by SWATCH-2299
- Covered by contract: It's swatch_contract_usage_total : Added by
SWATCH-2300
- Billing pending: It's swatch_billable_usage_total Added by SWATCH-2301
- Remitted: It`s swatch_producer_metered_total  Added by SWATCH-2302

The new "Metered end-to-end stats" panels look like as:

![Screenshot From 2025-02-07
10-29-21](https://github.com/user-attachments/assets/d484eaa6-8869-44b5-a8da-7391352b23b4)

Which displays the values by the select product(s), metric and billing
provider.

As part of this task, I found the following issues:
- The metric "swatch_billable_usage_total" is being counting twice:
SWATCH-3294
- The metric "swatch_tally_tallied_usage_total" is always empty. I will
dig further into this issue.

Additionally to the above panels, I've also added more panels to see
this data by metric:

![Screenshot From 2025-02-07
10-33-23](https://github.com/user-attachments/assets/e3956224-85c6-4fde-955d-32e58316a789)

The main difference is that we can see the number for all the metrics at
once without needing to pick up one concrete metric.

## Testing
Extract the new dashboard json using `oc extract -f
.rhcicd/grafana/grafana-dashboard-subscription-watch-payg-metrics.configmap.yaml
--confirm`

Once you extract it from the .yaml that's checked into this repo, you
can import it into the stage instance of grafana by going to `Dashboards
-> +Import` from the left nav.