Preserve newlines around notes

[madig]

@Hoolean found an unfortunate roundtripping hindrance:

1. ufoLib adds newlines around notes
2. ufonormalizer preserves them
3. Norad strips them
4. ufonormalizer preserves that, too.

Norad trims all text in the .glif XML on read:

norad/src/glyph/parse.rs

Line 47 in fe37cc9

reader.config_mut().trim_text(true);

Maybe it should be more selective in its trimming, see https://docs.rs/quick-xml/latest/quick_xml/reader/struct.Config.html#method.trim_text.

[RickyDaMa]

It sounds reasonable to me to have norad do the same \n{note}\n wrapping that the Python does, preserving the stripping on reading

[cmyr]

so this does raise lots of questions like "is it okay to insert a newline if there wasn't one there when we loaded", but... maybe we don't need to overthink this? I think it's reasonable if we add them on save and strip them on load.

[cmyr]

thanks!