Add indicator of data quality in final table

We have a hierarchy of trust in upstream data sources when undertaking the matching. None of the sources are complete, so the resulting data table is a patchwork of different sources.

It would be useful to have a quality grade assigned to every final attribute based on how far down this hierarchy it was necessary to go to access the data. That way, it's a bit clearer to a user when they are making use of lower "quality" data. Quality is subjective and might be best assigned by allowing the user to define trust levels per source and then calculating score per attribute based on that trust level.

This would likely need to be a table of the same shape as the final powerplants table with a score per attribute.

And example of some kind of system for this is in the TZ scenario builder docs

No implementation files or tests are named. Start by tracing how upstream sources are combined into the final powerplants table, then review the linked TZ scenario builder documentation and the existing source hierarchy. Done should be defined as a per-attribute quality result for the final table, with a clear way for users to provide source trust levels.