Add new syntax variant for pattern string anonymizer

[pounard]

In #224 @SimonMellerin suggested:

anonymization:
    default:
        customer:
            biography:
                anonymizer: pattern
                options: 
                     value: '{1} {2} has email address {3}.'
                     1: firstname
                     2: lastname
                     3: 
                         anonymizer: email
                         options: {domain: 'custom-domain.com'}

Let's think about that and implement it whenever we can.

[SimonMellerin]

duplicate of #229