feat(ui): add custom theme color support and share app functionality

Introduce a new custom theme feature that allows users to personalize the application background color using RGB sliders, hex input, or a set of predefined palettes.

Key changes include:
* **Custom Theme Engine**: Added `CustomThemeFragment` and `ThemeHelper` to manage color selection and application. The UI dynamically updates the background color across the `MainActivity` and `PlayerFragment` when preferences change.
* **Android TV Support**: Provided a specialized layout for television devices (`fragment_custom_theme.xml` in `layout-television`) with optimized focus handling for D-pad navigation.
* **Share Feature**: Implemented a "Share App" preference in `SettingsFragment` that triggers a standard Android share intent and displays a thank-you notification upon use.
* **Localization**: Added Ukrainian language support and updated string resources for multiple locales (DE, DA, EL, FR, JA, NL, PL, RU) to include the new theme and share options.
* **Persistence**: Updated `PreferencesHelper` and `Keys` to store theme-related settings, including the enabled state, selected color, and predefined color index.

app/src/main/java/com/michatec/radio/PlayerFragment.kt

@@ -308,6 +308,9 @@ class PlayerFragment : Fragment(),
         if (key == Keys.PREF_PLAYER_METADATA_HISTORY) {
             requestMetadataUpdate()
         }
+        if (key == Keys.PREF_CUSTOM_THEME_COLOR || key == Keys.PREF_CUSTOM_THEME_ENABLED || key == Keys.PREF_CUSTOM_THEME_INDEX) {
+            layout.applyCustomTheme(activity as Context)
+        }
     }