[feature] Transaction callback

[tianyiw2013]

Added Method:

• onActionCommitted
• onActionRolledBack
• onActionFinished

Added Test:

• ActionTest::testActionCommit
• ActionTest::testActionRollBack

Demo:

$medoo = new Medoo(...);
$medoo->action(function (Medoo $medoo) {
    $medoo->onActionCommitted(function (Medoo $medoo) {
        echo 'Action Committed', PHP_EOL;
        // For example: Stores the user's Avatar in the storage when the transaction is executed successfully, 
    });

    $medoo->onActionRolledBack(function (Medoo $medoo) {
        echo 'Action RolledBck', PHP_EOL;
        // For example: Delete the temporary file when the transaction fails.
    });

    $medoo->onActionFinished(function (Medoo $medoo, bool $commited) {
        echo 'Action Finished', PHP_EOL;
    });

});

My English is very poor. Please correct any grammar mistakes. thanks

[tianyiw2013]

ping @catfan
Any questions?