German translations do not use umlauts (ä, ö, ü, ß)

[chaehni]

Summary
The German localization in Submersion renders text without proper umlauts. Words that should contain ä, ö, ü, or ß appear with ae, oe, ue, or ss which looks weird to native speakers.

Steps to reproduce

1. Set Submersion language to German (Deutsch)
2. Navigate through the UI (menus, dialogs, tooltips, dive list columns, preferences)
3. Observe strings that should contain umlauts

Expected behavior
German strings render with correct umlauts, e.g.:

• "Tauchgaenge" -> "Tauchgänge"
• "Loeschen" -> "Löschen"
• "Tauchplaetze" -> "Tauchplätze"
• "Ueber" -> "Über"

Actual behavior
Umlauts are replaced with their ASCII equivalents (ae, oe, ue, ss).

[Apoplexi]

This seems like a simple problem. The texts are defined in \lib\l10n\arb\app_de.arb.
@ericgriffin If you agree, I could maintain this file for the German translation.