Add HEIC and WEBP support when dynamically resolving embedded images from classpath

Could you add support for the HEIC image format (`image/heic`)?
Would it be enough to just add it [here](https://github.com/bbottema/simple-java-mail/blob/6d2049387a4c31f08b879a34d657cab2c325942b/modules/core-module/src/main/java/org/simplejavamail/internal/util/ImageMimeType.java#L13)?