Add mpdf watermark text attribute

[thiago-you]

Scope

This pull request includes a

• [x] New feature

Changes

The following changes were made:

• Include option to append the mpdf watermark text attribute

[thiago-you]

Mpdf have a lot of extra attributes. So its better to create an adapter that extends the yii2-mpdf and implement the required new features/properties.

[kartik-v]

You can achieve this without adding new properties for every mpdf setup this way as shown below (for your water marker):

use kartik\mpdf\Pdf;

$pdf = new Pdf([
    'methods' => [
        'SetWatermarkText' => '<your watermark text>',
    ],
    'options' => [
        'showWatermarkText' => true,
    ]
]);
// then wherever you need to render
echo $pdf->render();

[thiago-you]

Thanks Kartik. I had not seen the "methods" in the documents.