all: cross fork monolith-types (#9)

* all: plumbing to get fork-monolith support in

* all: hack together the monolith ssz generator

* cmd/sszgen: monolith code generator + polishes + tests

* cmd/sszgen: fix a formatting error

* tests: regenerate ssz codecs to fix merge issues

* tests: fix another merge issue

* various wip snippets for integration testing

* ssz, tests: support operating on zero values across the board

* ssz, tests: rework monolith API to support clearing pointer fields

* cmd, ssz, tests: implement a bunch more monolithic type support

* ssz, tests: fix weird false failure reporting

* cmd, ssz, tests: add a fe wmore missing monolith field encoders

cmd/sszgen/forks.go

@@ -0,0 +1,39 @@
+// ssz: Go Simple Serialize (SSZ) codec library
+// Copyright 2024 ssz Authors
+// SPDX-License-Identifier: BSD-3-Clause
+
+package main
+
+// forkMapping maps fork names to fork values. This is used internally by the
+// ssz codec generator to convert tags to values.
+var forkMapping = map[string]string{
+	"unknown":        "Unknown",
+	"frontier":       "Frontier",
+	"homestead":      "Homestead",
+	"dao":            "DAO",
+	"tangerine":      "Tangerine",
+	"spurious":       "Spurious",
+	"byzantium":      "Byzantium",
+	"constantinople": "Constantinople",
+	"istanbul":       "Istanbul",
+	"muir":           "Muir",
+	"phase0":         "Phase0",
+	"berlin":         "Berlin",
+	"london":         "London",
+	"altair":         "Altair",
+	"arrow":          "Arrow",
+	"gray":           "Gray",
+	"bellatrix":      "Bellatrix",
+	"paris":          "Paris",
+	"merge":          "Merge",
+	"shapella":       "Shapella",
+	"shanghai":       "Shanghai",
+	"capella":        "Capella",
+	"dencun":         "Dencun",
+	"cancun":         "Cancun",
+	"deneb":          "Deneb",
+	"pectra":         "Pectra",
+	"prague":         "Prague",
+	"electra":        "Electra",
+	"future":         "Future",
+}