* 🐛 Ensure typography-ref attrs are always present and fix nil encoding
Add :typography-ref-file and :typography-ref-id (both defaulting to nil)
to default-text-attrs so these keys are always present in text node maps,
whether or not a typography is attached.
Skip nil values in attrs-to-styles (Draft.js style encoder) and in
attrs->styles (v2 CSS custom-property mapper) so nil typography-ref
entries are never serialised to CSS.
Replace when with if/acc in get-styles-from-style-declaration to prevent
the accumulator from being clobbered to nil when a mixed-value entry is
skipped during style decoding.
* 🎉 Add test
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Co-authored-by: Andrey Antukh <niwi@niwi.nz>
0c60db56a2