Keep sort order from original provider

[euzu]

The current implementation does not respect the provider order and sorts the playlist randomly without sort attribues set in config.

[ajuratovic]

I noticed the same issue when the sequence is used. Previously, only a sequence would be applied; now ordering is applied alongside the sequence.

This was introduced in the last or second-to-last release.

[euzu]

I have added a source_ordinal, which marks the original position of entries in the provider playlist.
If everything is implemented correctly, the provider order should be preserved when no sorting is applied.

[euzu]

Should be working in 3.2.41