feat(node): validator reward skeleton implementation

Cargo.toml

@@ -35,6 +35,8 @@ members = [
   "fendermint/vm/*",
   "fendermint/actors",
   "fendermint/actors/chainmetadata",
+  "fendermint/actors/gas_market",
+  "fendermint/actors/activity-tracker",
 ]
 
 [workspace.package]
@@ -217,6 +219,7 @@ fil_actor_eam = { git = "https://github.com/filecoin-project/builtin-actors", ta
 fil_actors_runtime = { git = "https://github.com/filecoin-project/builtin-actors", tag = "v12.0.0" }
 
 fendermint_actor_eam = { path = "./fendermint/actors/eam" }
+fendermint_actor_activity_tracker= { path = "./fendermint/actors/activity-tracker" }
 
 cid = { version = "0.10.1", default-features = false, features = [
   "serde-codec",