Revert back to directly setting private attr

-To bring back the functionality of the glyph dialog that pops up all
the errors on hitting save
-Breaks the dialog temporarily, there’s an issue with the validation on
the name field
Use setters!

Fixes bug where new glyph names were causing errors. Due to
subscriptions setting values directly instead of going through the
setters (with validation), the displayValue of the glyph name was
invalid at first due to being blank, but the flag was never cleared
since validation never happened after it was set