This commit renames the files relating to the diagnostic query that produces information on the number of files extracted. The files have been renamed from "SuccessfullExtractedFiles.*" to "ExtractedFiles.*". All related tests and test files have been renamed too.
The `@tags` and `@id` attributes of the queries have been left untouched, consistent with the `@tags` and `@id` for similar queries in other languages.
