Improvements to home page customization (#1458)

## Description
Adds a few enhancements to home page customization:
- Add option to combined continue watching & next up to split it
- Add option to continue watching and next up rows to combine them
- Add option for sorting playlist or collections
- Show suggestions (recently updated) when searching for a playlist or
collection to add
- Better handling for loading vs unsupported types for suggestions

Also, the old toggle for combining continue watching & next up in
advanced settings is removed. Now by default the rows will be combined
unless changed in the home page customization settings.

### Related issues
Closes #340
Closes #1383
Closes #1350

### Testing
Just on the emulator so far

## Screenshots
N/A

## AI or LLM usage
None

app/src/main/java/com/github/damontecres/wholphin/preferences/AppPreference.kt

@@ -202,18 +202,6 @@ sealed interface AppPreference<Pref, T> {
                 },
             )
 
-        val CombineContinueNext =
-            AppSwitchPreference<AppPreferences>(
-                title = R.string.combine_continue_next,
-                defaultValue = false,
-                getter = { it.homePagePreferences.combineContinueNext },
-                setter = { prefs, value ->
-                    prefs.updateHomePagePreferences { combineContinueNext = value }
-                },
-                summaryOn = R.string.enabled,
-                summaryOff = R.string.disabled,
-            )
-
         val RewatchNextUp =
             AppSwitchPreference<AppPreferences>(
                 title = R.string.rewatch_next_up,
@@ -1202,7 +1190,6 @@ val advancedPreferences =
                         AppPreference.BackdropStylePref,
                         AppPreference.ShowLogos,
                         AppPreference.ManageMedia,
-                        AppPreference.CombineContinueNext,
                         AppPreference.DisplayTogglesPref,
                         // Temporarily disabled, see https://github.com/damontecres/Wholphin/pull/127#issuecomment-3478058418
 //                    AppPreference.NavDrawerSwitchOnFocus,

app/src/main/java/com/github/damontecres/wholphin/preferences/AppPreferencesSerializer.kt

@@ -85,7 +85,6 @@ class AppPreferencesSerializer
                             .apply {
                                 maxItemsPerRow = AppPreference.HomePageItems.defaultValue.toInt()
                                 enableRewatchingNextUp = AppPreference.RewatchNextUp.defaultValue
-                                combineContinueNext = AppPreference.CombineContinueNext.defaultValue
                                 maxDaysNextUp = AppPreference.MaxDaysNextUp.defaultValue.toInt()
                             }.build()
                     interfacePreferences =