PieceDirectory deal cleanup

[LexLuthr]

1. Expired deals should be cleaned up - Should be user defined not automatic in case SP wants to keep serving from expired deals.
2. Slashed deals should be cleaned up (where retrieval cannot be served) - this should be automated Ex: sector no longer available
3. Deal details should be removed from piece metadata
4. Index should be removed for pieces where no more deals are left after deal cleanup
5. Announcement should be made to indexer that these MultiHashes are no longer available.

[LexLuthr]

• Implement Basic Removal APIs feat: piecedirectory cleanup #953
• Take a decision on how to track legacy deals in Metadata as it only has UUID
• Add a cleanup job in Legacy Provider and Boost Provider
• Update Indexer about removed deals if required