* rough draft of potential parent search
* get things compiling
* fmt
* add new function to all RelayChainInterface implementations
* fix compilation
* set slot and timestamp based on relay parent, prepare for find-parent
* skeleton of new aura logic
* fmt
* introduce a collator module in the Aura crate
* extract different implementations into own modules
* make interface more convenient
* docs and todos for lookahead
* refactor basic collator to use new collator utility
* some more refactoring
* finish most of the control flow for new aura
* introduce backend as parameter
* fix compilation
* fix a couple more TODOs
* add an `announce_block` function to collator service
* announce with barrier
* rename block announcement validator to be more specific
* fmt
* clean up unused import errors
* update references to BlockAnnounceValidator
* rename unstable_reimpl
* add AuraUnincludedSegmentApi
* finish rename
* integrate AuraUnincludedSegmentApi
* add a new block announcement validator for backwards compatibility
* add some naive equivocation defenses
* rustfmt
* clean up remaining TODO [now]s
* fmt
* try to fix inprocess-interface
* actually fix compilation
* ignored -> rejected rephrase
* fix test compilation
* fmt
* clippy