Logs volume: update DataSourceWithSupplementaryQueriesSupport implementation

[matyax]

In https://github.com/grafana/grafana/pull/80281 the interface was updated to deprecate getDataProvider in favor of getSupplementaryRequest, so data sources that need decoupling from Grafana Core don't depend on queryLogsVolume().

[matyax]

Addressing the deprecation should be as simple as renaming getDataProvider to getSupplementaryRequest, and return the request instead of the Observable from queryLogsVolume(), but I see that you have a custom queryLogsVolume implementation that seems to also be doing aggregation and other modifications to the response: https://github.com/grafana/clickhouse-datasource/blob/main/src/data/logs.ts#L75C38-L83

Feel free to ping, I'll be happy to help.