ToolsKit HEIC decoder notices

The HEIC to JPG tool uses libheif-js 1.23.5, an Emscripten build of
libheif, distributed under LGPL-3.0. The library's JavaScript and WebAssembly
files are copied unmodified from the pinned npm package. They are loaded
separately from the ToolsKit application, inside a per-photo Web Worker.

Package: https://www.npmjs.com/package/libheif-js/v/1.23.5
JavaScript package source and build scripts:
https://github.com/catdad-experiments/libheif-js/tree/d8ec4bc3bc5bf8055975577bccbbc7e1d7313c2d
Corresponding Emscripten build and upstream source references:
https://github.com/catdad-experiments/libheif-emscripten/tree/v1.23.5
Build release used by that package:
https://github.com/catdad-experiments/libheif-emscripten/releases/tag/v1.23.5
Upstream libheif: https://github.com/strukturag/libheif

License texts are served next to this notice as LICENSE and
libheif-js.LICENSE. The library and its dependencies retain their respective
copyrights and license terms. See the versioned build repository for source,
dependency revisions and instructions for rebuilding the decoder.

To use a compatible modified decoder in a local ToolsKit build, replace
libheif.js and libheif.wasm in public/vendor/heic/1.23.5 after running the
asset exporter. The application calls the published libheif C/Embind APIs;
it does not require a proprietary decoder service or an account.
No Terms restriction on reverse engineering for debugging modifications
to these LGPL components is imposed by ToolsKit.