Document the process of using OData endpoints for data visualisation

Problem

Follow on from #1440

FMTM facilitates data collection.
OData endpoints are a standardised way to ingest this data into other tools: PowerBI, Tableau, Redash, Grafana
ODK already has good docs on this that we should link to: https://docs.getodk.org/tutorial-mapping-households/

We probably need some extra docs to help flesh out how this can be achieved (based on actual requirements from a mapping project):
- Submission history for each enumerator
- Custom date range filtering of submissions
- Total submissions vs total number features surveyed
- Filter submissions by tasks
- Average submission time per enumerator
- Expected number of submissions vs actual daily submissions
- Leaderboard based on submission
Yes, PowerBI is proprietary, but it's free to use, very powerful, and user friendly. We need to be realistic and suggest the easiest solution that most end users will connect with. I would propose we document the process for PowerBI first.

(from previous thread)

Describing various options in different forms.

PowerBI is the simplest and most powerful. The files can be shared with other users of PowerBI Desktop. The dashboards cannot easily be shared on web however.
Excel can also load OData, but it's not as visually appealing or easy to use as PowerBI.
Haven't tested Tableau, but it's meant to be good (less powerful that PowerBI).

Note with these options we need to pay to host them...

~Redash, acquired by databricks… (limping on as OSS currently, so let's see where it goes)~
~Apache Superset & Metabase don’t support OData~
Grafana has an OData plugin and is a fantastic CNCF project.
- Probably our best choice until we discover something else.
- A bit of a pain to configure the data provider / dashboard, but works.
- https://grafana.com/grafana/plugins/dvelop-odata-datasource/
- Docker compose config to test it:
```
services:
grafana:
image: grafana/grafana-oss:11.2.0
container_name: grafana
restart: unless-stopped
ports:
 - '3022:3000'
environment:
  GF_INSTALL_PLUGINS: dvelop-odata-datasource
volumes:
  - grafana-storage:/var/lib/grafana
```
volumes: grafana-storage:

We could possibly use the XOData chrome extension, but it looks a bit old. Not tested.
Final option is to make our own simple dashboard using a Graph library (charts.js or Apache ECharts) and HTML tables.
- The creds for OData endpoints would need either be:
- Embedded in the web app - not an option 😅
- Configured by the user - not that user friendly.

In summary this is a tough decision!

Recommendation:

Have simple visualisations for most common requirements built into FMTM (as we do currently, but improved upon).
For more complex / bespoke needs, just ask the user to install PowerBI and make a dashboard (this could be done for them by sharing a pre-configured .pbix file dashboard).