6 files declare their use of ImageFieldMapping in FillPDF 8.4

FillPdfServicePdfBackend.php in src/Plugin/PdfBackend/FillPdfServicePdfBackend.php

ImageFieldMappingTest.php in tests/src/Unit/FieldMapping/ImageFieldMappingTest.php

LegacyProviderPdfBackend.php in modules/fillpdf_legacy/src/Plugin/PdfBackend/LegacyProviderPdfBackend.php

LocalServerPdfBackend.php in src/Plugin/PdfBackend/LocalServerPdfBackend.php

PdfPopulationTest.php in tests/src/Functional/PdfPopulationTest.php

TokenResolver.php in src/TokenResolver.php