Cleanup editor translation related methods

- Unify logic for loading editor/property/doc/extractable translations.
- Replace legacy `TranslationServer` methods with translation domains for internal translations.
- Only pre-create editor/property/doc translation domains in editor builds.
- Prevent adding `null` translation.
- Fixes potential loading of duplicated editor translations.
- Add internal `has_translation_for_locale()` instead of calling `get_loaded_translations().has()`.

editor/editor_builders.py

@@ -124,7 +124,7 @@ inline constexpr const unsigned char _{category}_translation_{name}_compressed[]
         file.write(f"""\
 #include "{target_h}"
 
-const {category.capitalize()}TranslationList _{category}_translations[] = {{
+const EditorTranslationList _{category}_translations[] = {{
 """)
 
         for x in xl_names:
@@ -137,12 +137,18 @@ const {category.capitalize()}TranslationList _{category}_translations[] = {{
 
     with methods.generated_wrapper(target_h) as file:
         file.write(f"""\
-struct {category.capitalize()}TranslationList {{
+
+#ifndef EDITOR_TRANSLATION_LIST
+#define EDITOR_TRANSLATION_LIST
+
+struct EditorTranslationList {{
 	const char* lang;
 	int comp_size;
 	int uncomp_size;
 	const unsigned char* data;
 }};
 
-extern const {category.capitalize()}TranslationList _{category}_translations[];
+#endif // EDITOR_TRANSLATION_LIST
+
+extern const EditorTranslationList _{category}_translations[];
 """)