Add overrideFields to FlexFormProcessor

[ducrot]

Configure individual fields of the FlexFormProcessor result. Same as overrideFields in DatabaseQueryProcessor, but for FlexFormProcessor (see also: bf8da47). Allows to convert typolinks, images, ...

Example

10 = FriendsOfTYPO3\Headless\DataProcessing\FlexFormProcessor
10 {
    fieldName = pi_flexform
    as = flexform
    overrideFields {
        image = TEXT
        image {
            dataProcessing {
                10 = FriendsOfTYPO3\Headless\DataProcessing\FilesProcessor
                10 {
                    references {
                        table = tt_content
                        fieldName = image
                    }
                    as = image
                }
            }
        }
        link = TEXT
        link {
            field = link
            htmlSpecialChars = 1
            typolink {
                parameter {
                    field = link
                }
                returnLast = result
            }
        }
    }
}

Result without overrideFields

{
  "flexform": {
	"image": "1",
	"link": "t3:\/\/page?uid=13"
  }
}

Result with overrideFields

{
  "flexform": {
	"image": [
	  {
		"publicUrl": "http:\/\/web.domain.test\/fileadmin\/media\/testimage.png",
		"properties": {
		  "title": null,
		  "alternative": null,
		  "description": null,
		  "link": null,
		  "linkData": null,
		  "mimeType": "image\/png",
		  "type": "image",
		  "filename": "testimage.png",
		  "originalUrl": "\/fileadmin\/media\/testimage.png",
		  "uidLocal": 3370,
		  "fileReferenceUid": 9518,
		  "size": "15 KB",
		  "dimensions": {
			"width": 500,
			"height": 300
		  },
		  "cropDimensions": {
			"width": 500,
			"height": 300
		  },
		  "crop": {
			"default": {
			  "cropArea": {
				"x": 0,
				"y": 0,
				"width": 1,
				"height": 1
			  },
			  "selectedRatio": "NaN",
			  "focusArea": null
			}
		  },
		  "autoplay": null,
		  "extension": null
		}
	  }
	],
	"link": {
	  "href": "\/demo\/link",
	  "target": null,
	  "class": null,
	  "title": null,
	  "linkText": "t3:\/\/page?uid=13",
	  "additionalAttributes": []
	}
  }
}

[coveralls]

Pull Request Test Coverage Report for Build 4305780310

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 61.597%

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Totals
Change from base Build 4305600549:	0.0%
Covered Lines:	725
Relevant Lines:	1177

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💛 - Coveralls