Allow for request parameter transformations

[corazzi]

Different forms may make requests with different request parameters for the same data.

For example, one form may send a parameter of minDateand another form may send a parameter of minimumDate, but both need to map to the filterMinimumDate() method.

A $transforms property could look like this:

protected $transforms = [
    'minDate' => 'minimumDate'
];

The resolver will call a performTransformations() method before running each mapped filter which will set a request parameter of minimumDate to be the value of the existing request parameter minDate.

protected $map = [
    'minimumDate' => 'filterMinimumDate',
]

protected $transforms = [
    'minDate' => 'minimumDate',
    'dateMin' => 'minimumDate',
    'fromDate' => 'minimumDate',
];

Now it won't matter if the form sends minDate, dateMin, fromDate, or mimimumDate – it will always be mapped to the filterMinimumDate method.