Substitute platform names with eventyay in translated languages

[mariobehling]

Currently, some translated strings across the project still contain generic platform names (e.g., Open Event, Tickets Platform) or outdated branding. To maintain consistency, all translations should use “eventyay” as the platform name, while keeping the rest of the sentence structure in the target language.

Tasks

• Search .po and .mo files (and .arb/localization files if present) for occurrences of old platform names.
• Replace them with eventyay in all supported languages.
• Ensure capitalization and grammatical placement fit the translated context (e.g., declensions in German, plural forms if needed).
• Verify no English fallback strings are left with outdated names.
• Rebuild translations and check UI to confirm changes are reflected.