Add Fulu boilerplate (#6695)

* Add Fulu boilerplate

* Add more boilerplate

* Change fulu_time to osaka_time

* Merge branch 'unstable' into fulu-boilerplate

* Fix tests

* Merge branch 'unstable' into fulu-boilerplate

* More test fixes

* Apply suggestions

* Remove `get_payload` boilerplate

* Add lightclient fulu types and fix beacon-chain-tests

* Disable Fulu in ef-tests

* Reduce boilerplate for future forks

* Small fixes

* One more fix

* Apply suggestions

* Merge branch 'unstable' into fulu-boilerplate

* Fix lints

consensus/types/presets/gnosis/fulu.yaml

@@ -0,0 +1,3 @@
+# Gnosis preset - Fulu
+
+FULU_PLACEHOLDER: 0

consensus/types/presets/mainnet/fulu.yaml

@@ -0,0 +1,3 @@
+# Mainnet preset - Fulu
+
+FULU_PLACEHOLDER: 0

consensus/types/presets/minimal/fulu.yaml

@@ -0,0 +1,3 @@
+# Minimal preset - Fulu
+
+FULU_PLACEHOLDER: 0