Builder flow for Deneb & Blobs (#4428)

* Add Deneb builder flow types with generics

* Update validator client `get_blinded_blocks` call to support Deneb

* `produceBlindedBlock` endpoint updates:
- Handle new Deneb BuilderBid response from builder endpoint (new BlindedBlobsBundle type)
- Build BlockContents response (containing kzg_commitments, proof and blinded_blob_sidecars)

* Appease Clippy lint

* Partial implementation of submit blinded block & blobs. Refactor existing `BlobSidecar` related types to support blinded blobs.

* Add associated types for BlockProposal

* Rename `AbstractSidecar` to `Sidecar`

* Remove blob cache as it's no longer necessary

* Remove unnecessary enum variant

* Clean up

* Hanlde unblinded blobs and publish full block contents

* Fix tests

* Add local EL blobs caching in blinded flow

* Remove BlockProposal and move associated Sidecar trait to AbstractExecPayload to simplify changes

* add blob roots associated type

* move raw blobs associated type to sidecar trait

* Fix todos and improve error handling

* Consolidate BlobsBundle from `execution_layer` into `consensus/types`

* Rename RawBlobs, Blobs, and BlobRoots

* Use `BlobRoots` type alias

* Update error message.

Co-authored-by: realbigsean <seananderson33@GMAIL.com>

* update builder bid type

# Conflicts:
#	consensus/types/src/builder_bid.rs

* Fix lint

* remove generic from builder bid

---------

Co-authored-by: realbigsean <seananderson33@gmail.com>

validator_client/src/signing_method.rs

@@ -37,7 +37,7 @@ pub enum Error {
 pub enum SignableMessage<'a, T: EthSpec, Payload: AbstractExecPayload<T> = FullPayload<T>> {
     RandaoReveal(Epoch),
     BeaconBlock(&'a BeaconBlock<T, Payload>),
-    BlobSidecar(&'a BlobSidecar<T>),
+    BlobSidecar(&'a Payload::Sidecar),
     AttestationData(&'a AttestationData),
     SignedAggregateAndProof(&'a AggregateAndProof<T>),
     SelectionProof(Slot),