Rename emulationstation-de to es-de

[bentley]

According to the upstream FAQ (https://gitlab.com/es-de/emulationstation-de/-/blob/master/FAQ.md):

“As of the 3.0.0 release the official name for the project and application is ES-DE Frontend or simply ES-DE.”

[bentley]

This is really a merge, not just a rename, because Repology has the same project under multiple names:

• https://repology.org/project/es-de/versions
• https://repology.org/project/emulationstation-de/versions