Builder Specs v0.2.0 (#3134)

## Issue Addressed

#3091

Extends #3062, adding pre-bellatrix block support on blinded endpoints and allowing the normal proposal flow (local payload construction) on blinded endpoints. This resulted in better fallback logic because the VC will not have to switch endpoints on failure in the BN <> Builder API, the BN can just fallback immediately and without repeating block processing that it shouldn't need to. We can also keep VC fallback from the VC<>BN API's blinded endpoint to full endpoint.

## Proposed Changes

- Pre-bellatrix blocks on blinded endpoints
- Add a new `PayloadCache` to the execution layer
- Better fallback-from-builder logic

## Todos

- [x] Remove VC transition logic
- [x] Add logic to only enable builder flow after Merge transition finalization
- [x] Tests
- [x] Fix metrics
- [x] Rustdocs


Co-authored-by: Mac L <[email protected]>
Co-authored-by: realbigsean <[email protected]>

.github/workflows/local-testnet.yml

@@ -40,13 +40,29 @@ jobs:
         run: make && make install-lcli
 
       - name: Start local testnet
-        run: ./start_local_testnet.sh
+        run: ./start_local_testnet.sh && sleep 60
         working-directory: scripts/local_testnet
 
       - name: Print logs
-        run: ./print_logs.sh
+        run: ./dump_logs.sh
         working-directory: scripts/local_testnet
 
       - name: Stop local testnet
         run: ./stop_local_testnet.sh
         working-directory: scripts/local_testnet
+
+      - name: Clean-up testnet
+        run: ./clean.sh
+        working-directory: scripts/local_testnet
+
+      - name: Start local testnet with blinded block production
+        run: ./start_local_testnet.sh -p && sleep 60
+        working-directory: scripts/local_testnet
+
+      - name: Print logs for blinded block testnet
+        run: ./dump_logs.sh
+        working-directory: scripts/local_testnet
+
+      - name: Stop local testnet with blinded block production
+        run: ./stop_local_testnet.sh
+        working-directory: scripts/local_testnet