feat!: abra app env pull

`abra app env` -> `abra app env list`.

See toolshed/abra#497

cli/run.go

@@ -283,6 +283,11 @@ Config:
 		app.AppBackupSnapshotsCommand,
 	)
 
+	app.AppEnvCommand.AddCommand(
+		app.AppEnvListCommand,
+		app.AppEnvPullCommand,
+	)
+
 	app.AppCommand.AddCommand(
 		app.AppBackupCommand,
 		app.AppCheckCommand,