Project name rename
gnome-characters has been using its namespace as its name which eases some building steps in autotools. This might cause some issues with meson because it uses this value in a different way for some steps (ninja dist package name).
However, meson is able to separate these concepts so the project name can been changed and use the namespace in different build steps.
This MR renames the project name to
gnome-characters and the namespace is used for the necessary build steps.