Characters with diacritic marks can in Unicode be represented either as a single codepoint (e.g. "Ä"), or as a combination (e.g. "A" + "¨"). Most systems use the single codepoint, and it is what we expect from keyboard layouts as it is what we need for VNC/RFB/X11. But macOS likes the decomposed system with multiple codepoints. For keyboards it mostly stays sane with single codepoints, but at least the Hebrew layout uses decomposed symbols in some cases. E.g. it can send U+05E9 + U+05C1 rather than the composed U+FB2B. It looks like we need to normalise these so we can figure out what to send to the server.
Oddly enough, the related Yiddish layout doesn't have this issue with the exact same character. It generates the composed codepoint. The issue doesn't happen on Windows as it doesn't have the problematic symbol. Linux is also fine as there is no mechanism to send multiple values per key, so it has to use a composed version.
