The names are now based on where the strings are used in the GUI. This
will hopefully make it easier for translators to locate where they are
in the user interface.
I've prefixed all translatable string names with "tr-" to prevent
accidentally substitute unrelated strings in a mass replace.
Once I push this commit, I will also protect `locales/**`, so that
all future changes to strings pass a PR review process to reduce the
probability of errors. This will also make it easier to have a freeze
for translatable strings if we end up having a release schedule in the
future.