XYZ-37: Advanced Permissions Phase 1 Backend. (#8159)

* XYZ-13: Update Permission and Role structs to new design.

* XYZ-10: Role store.

* XYZ-9/XYZ-44: Roles API endpoints and WebSocket message.

* XYZ-8: Switch server permissions checks to store backed roles.

* XYZ-58: Proper validation of roles where required.

* XYZ-11/XYZ-55: Migration to store backed roles from policy config.

* XYZ-37: Update unit tests to work with database roles.

* XYZ-56: Remove the "guest" role.

* Changes to SetDefaultRolesFromConfig.

* Short-circuit the store if nothing has changed.

* Address first round of review comments.

* Address second round of review comments.

store/sqlstore/supplier.go

@@ -86,6 +86,7 @@ type SqlSupplierOldStores struct {
 	userAccessToken      store.UserAccessTokenStore
 	plugin               store.PluginStore
 	channelMemberHistory store.ChannelMemberHistoryStore
+	role                 store.RoleStore
 }
 
 type SqlSupplier struct {
@@ -135,6 +136,7 @@ func NewSqlSupplier(settings model.SqlSettings, metrics einterfaces.MetricsInter
 	supplier.oldStores.plugin = NewSqlPluginStore(supplier)
 
 	initSqlSupplierReactions(supplier)
+	initSqlSupplierRoles(supplier)
 
 	err := supplier.GetMaster().CreateTablesIfNotExists()
 	if err != nil {
@@ -811,6 +813,10 @@ func (ss *SqlSupplier) Plugin() store.PluginStore {
 	return ss.oldStores.plugin
 }
 
+func (ss *SqlSupplier) Role() store.RoleStore {
+	return ss.oldStores.role
+}
+
 func (ss *SqlSupplier) DropAllTables() {
 	ss.master.TruncateTables()
 }