Fix transaction_mode parsing (#5963)
Fix transaction_mode parsing (#5963)

* Fix transaction_mode parsing and program exit if presented with an invalid transaction_mode option

Signed-off-by: Saif Alharthi <ab9e74884d0afee45981c0c80059c0dadb8a95da@saifalharthi.me>
mahak/vitess,vitessio/vitess,tinyspeck/vitess,mahak/vitess,mahak/vitess,vitessio/vitess,tinyspeck/vitess,mahak/vitess,tinyspeck/vitess,mahak/vitess,vitessio/vitess,vitessio/vitess,vitessio/vitess,tinyspeck/vitess,mahak/vitess,tinyspeck/vitess,vitessio/vitess,mahak/vitess,mahak/vitess,vitessio/vitess,vitessio/vitess,tinyspeck/vitess,tinyspeck/vitess