feat: add Ukrainian translation (#1065)

## Summary

* **What is the goal of this PR?**
A Ukrainian translation for the GUI

* **What changes are included?**
Everything according to
https://github.com/crosspoint-reader/crosspoint-reader/blob/master/docs/i18n.md

## Additional Context

* Add any other information that might be helpful for the reviewer
(e.g., performance implications, potential risks,
  specific areas to focus on).

Nope

---

### AI Usage

While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.

Did you use AI tools to help write this code? _**< PARTIALLY >**_ as a
consistency validation

lib/I18n/I18nKeys.h

@@ -15,6 +15,7 @@ extern const char* const STRINGS_RU[];
 extern const char* const STRINGS_SV[];
 extern const char* const STRINGS_RO[];
 extern const char* const STRINGS_CA[];
+extern const char* const STRINGS_UK[];
 }  // namespace i18n_strings
 
 // Language enum
@@ -29,6 +30,7 @@ enum class Language : uint8_t {
   SWEDISH = 7,
   ROMANIAN = 8,
   CATALAN = 9,
+  UKRAINIAN = 10,
   _COUNT
 };
 
@@ -383,6 +385,8 @@ inline const char* const* getStringArray(Language lang) {
       return i18n_strings::STRINGS_RO;
     case Language::CATALAN:
       return i18n_strings::STRINGS_CA;
+    case Language::UKRAINIAN:
+      return i18n_strings::STRINGS_UK;
     default:
       return i18n_strings::STRINGS_EN;
   }