allow changing cropped image mime type

[wing5wong]

Hi there

Id like to be able to crop images using the image upload as described here: https://mary-ui.com/docs/components/file#image-crop

with the current setup, i believe this always generates image/png versions of the image by default. I would like to be able to generate image/jpeg versions,

The cropperjs docs indicate we can change the mime type here - im not sure how you would want to approach the custom choice here in the File component. (https://github.com/fengyuanchen/cropperjs/blob/main/README.md#getcroppedcanvasoptions)

this.cropper.getCroppedCanvas().toBlob((blob) => {
                                blob.name = $refs.file.files[0].name
                                @this.upload('{{ $attributes->wire('model')->value }}', blob,
                                    (uploadedFilename) => {  },
                                    (error) => {  },
                                    (event) => { this.progress = event.detail.progress }
                                )
                            }, 'image/jpeg')

with this change, the user can set the mime type as follows
<x-file wire:model="photo" accept="image/png" crop-after-change cropMimeType="image/jpeg">

resolves #761