feat: Electron Fuses, package time feature toggles (#24241)

* feat: add new 'fuses' feature for package-time build-flag style feature control

* feat: put ENABLE_RUN_AS_NODE behind a fuse as well

* chore: address PR feedback

* build: move FUSE_EXPORT to headers

* build: use hex codes for kFuseWire char[]

* docs: add fuse wire documentation

* chore: update fuses.json info

* Apply suggestions from code review

Co-authored-by: Jeremy Rose <jeremya@chromium.org>

* chore: add link to fuse schema

* Update shell/app/electron_library_main.mm

Co-authored-by: Jeremy Rose <jeremya@chromium.org>

Co-authored-by: Jeremy Rose <jeremya@chromium.org>

BUILD.gn

@@ -303,6 +303,19 @@ templated_file("electron_version_header") {
   args_files = get_target_outputs(":electron_version_args")
 }
 
+action("electron_fuses") {
+  script = "build/fuses/build.py"
+
+  inputs = [ "build/fuses/fuses.json" ]
+
+  outputs = [
+    "$target_gen_dir/fuses.h",
+    "$target_gen_dir/fuses.cc",
+  ]
+
+  args = rebase_path(outputs)
+}
+
 source_set("electron_lib") {
   configs += [ "//v8:external_startup_data" ]
   configs += [ "//third_party/electron_node:node_internals" ]
@@ -313,6 +326,7 @@ source_set("electron_lib") {
   ]
 
   deps = [
+    ":electron_fuses",
     ":electron_js2c",
     ":electron_version_header",
     ":manifests",
@@ -657,6 +671,8 @@ source_set("electron_lib") {
       "shell/browser/electron_pdf_web_contents_helper_client.h",
     ]
   }
+
+  sources += get_target_outputs(":electron_fuses")
 }
 
 electron_paks("packed_resources") {