Adds webp to mime type map to support preview on upload file property editor. (#18863)

Author: AndyButland

src/Umbraco.Web.UI.Client/src/packages/media/media/components/input-upload-field/utils.ts

@@ -744,6 +744,7 @@ export function getMimeTypeFromExtension(extension: string): string | null {
 		'.wbxml': 'application/vnd.wap.wbxml',
 		'.wcm': 'application/vnd.ms-works',
 		'.wdb': 'application/vnd.ms-works',
+		'.webp': 'image/webp',
 		'.wiz': 'application/msword',
 		'.wks': 'application/vnd.ms-works',
 		'.wm': 'video/x-ms-wm',