Add Emission Enabled bolean flag to Mint Module (#708)

## Purpose of Changes and their Description

This change adds a mint module parameter that allows network
administrators or the `/x/gov` governance module to control whether or
not any new tokens are minted, basically entirely turning off paying for
rewards and creating new tokens / inflation.

## Link(s) to Ticket(s) or Issue(s) resolved by this PR

PROTO-3083

## Are these changes tested and documented?

New tests added to `x/mint/migrations/v5/migrate_test.go` and
`x/mint/module/module_test.go`

CHANGELOG.md

@@ -70,6 +70,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 * [#694](https://github.com/allora-network/allora-chain/pull/694) Make fuzzer whitelist aware
+* [#708](https://github.com/allora-network/allora-chain/pull/708) Add Emission Enabled bolean flag to Mint Module
 
 ### Fixed
 

app/upgrades.go

@@ -11,6 +11,7 @@ import (
 	"github.com/allora-network/allora-chain/app/upgrades/v0_5_0"
 	"github.com/allora-network/allora-chain/app/upgrades/v0_6_0"
 	"github.com/allora-network/allora-chain/app/upgrades/v0_7_0"
+	"github.com/allora-network/allora-chain/app/upgrades/v0_8_0"
 )
 
 var upgradeHandlers = []upgrades.Upgrade{
@@ -19,6 +20,7 @@ var upgradeHandlers = []upgrades.Upgrade{
 	v0_5_0.Upgrade,
 	v0_6_0.Upgrade,
 	v0_7_0.Upgrade,
+	v0_8_0.Upgrade,
 	// Add more upgrade handlers here
 	// ...
 }

app/upgrades/v0_8_0/upgrades.go

@@ -0,0 +1,31 @@
+package v0_8_0 //nolint:revive // var-naming: don't use an underscore in package name
+
+import (
+	"context"
+
+	storetypes "cosmossdk.io/store/types"
+	upgradetypes "cosmossdk.io/x/upgrade/types"
+	"github.com/allora-network/allora-chain/app/keepers"
+	"github.com/allora-network/allora-chain/app/upgrades"
+	"github.com/cosmos/cosmos-sdk/types/module"
+)
+
+const (
+	UpgradeName = "v0.8.0"
+)
+
+var Upgrade = upgrades.Upgrade{
+	UpgradeName:          UpgradeName,
+	CreateUpgradeHandler: CreateUpgradeHandler,
+	StoreUpgrades:        storetypes.StoreUpgrades{Added: nil, Renamed: nil, Deleted: nil},
+}
+
+func CreateUpgradeHandler(
+	moduleManager *module.Manager,
+	configurator module.Configurator,
+	keepers *keepers.AppKeepers,
+) upgradetypes.UpgradeHandler {
+	return func(ctx context.Context, plan upgradetypes.Plan, vm module.VersionMap) (module.VersionMap, error) {
+		return moduleManager.RunMigrations(ctx, configurator, vm)
+	}
+}