Currently this method always succeeds, but that won't be true once we
switch to the Core::Stream API. :^)
Some of these places would ideally show an error message to the user,
since failure to save a file is significant, but let's not get
distracted right now.
I've attempted to handle the errors gracefully where it was clear how to
do so, and simple, but a lot of this was just adding
`release_value_but_fixme_should_propagate_errors()` in places.
Makes CharacterMapFile::load_from_file and CharacterMap::load_from_file
return ErrorOr instead of Optional. This makes them a little nicer to
use and a little easier to read, as they seem to have been approximating
this.
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
