Add hooks to governance actions (cosmos#9133)

* add governance hooks

* fix lint

* fix lint

* CHANGELOG

* sh -> gh

* improve comments

* add test

* add more tests

* rename two of the hooks

Co-authored-by: ahmedaly113 <ahmedaly113@outlook.com>

app.go

@@ -273,11 +273,17 @@ func NewSimApp(
 		AddRoute(paramproposal.RouterKey, params.NewParamChangeProposalHandler(app.ParamsKeeper)).
 		AddRoute(distrtypes.RouterKey, distr.NewCommunityPoolSpendProposalHandler(app.DistrKeeper)).
 		AddRoute(upgradetypes.RouterKey, upgrade.NewSoftwareUpgradeProposalHandler(app.UpgradeKeeper))
-	app.GovKeeper = govkeeper.NewKeeper(
+	govKeeper := govkeeper.NewKeeper(
 		appCodec, keys[govtypes.StoreKey], app.GetSubspace(govtypes.ModuleName), app.AccountKeeper, app.BankKeeper,
 		&stakingKeeper, govRouter,
 	)
 
+	app.GovKeeper = *govKeeper.SetHooks(
+		govtypes.NewMultiGovHooks(
+		// register the governance hooks
+		),
+	)
+
 	// create evidence keeper with router
 	evidenceKeeper := evidencekeeper.NewKeeper(
 		appCodec, keys[evidencetypes.StoreKey], &app.StakingKeeper, app.SlashingKeeper,