Fix webp support for m1 macs

[spbolton]

Updating to use io.github.darkxanter:webp-imageio:0.3.2 https://github.com/darkxanter/webp-imageio for webp support, this is a fork of https://github.com/sejda-pdf/webp-imageio that is compiled with m1 binaries.

The package structure has changed so we need to change the hardcoded r instanceof net.sf.javavp8decoder.imageio.WebPImageReader to make use of the provided vendor name e.g. r.getOriginatingProvider().getVendorName().equals("Luciad"). This change is backwards compatible as our existing uses the same vendor name.

This allows the BinaryServletExporterTest to run directly on M1 macs.

requestGifFile has an byte encoded version of an output image as a test, there is minor change in the new version to the binary of the generated image so this is needed to be updated.