* feat: generalize ConsensusDataProvider for manual-seal

* rename all generic type param `proof`/`PROOF` to `P`

* rename a missing thing

* Update client/consensus/manual-seal/src/consensus.rs

Co-authored-by: Davide Galassi <davxy@datawok.net>

* Update client/consensus/manual-seal/src/consensus/babe.rs

Co-authored-by: Davide Galassi <davxy@datawok.net>

* Update client/consensus/manual-seal/src/consensus/aura.rs

Co-authored-by: Davide Galassi <davxy@datawok.net>

Co-authored-by: Davide Galassi <davxy@datawok.net>