Refactor notifications to Kotlin & paging (#4026)

This refactors the NotificationsFragment and related classes to Kotlin &
paging.
While trying to preserve as much of the original behavior as possible,
this adds the following improvements as well:
- The "show notifications filter" preference was added again
- The "load more" button now has a background ripple effect when clicked
- The "legal" report category of Mastodon 4.2 is now supported in report
notifications
- Unknown notifications now display "unknown notification type" instead
of an empty line

Other code quality improvements:
- All views from xml layouts are now referenced via ViewBindings
- the classes responsible for showing system notifications were moved to
a new package `systemnotifications` while the classes from this
refactoring are in `notifications`
- the id of the local Tusky account is now called `tuskyAccountId` in
all places I could find

closes https://github.com/tuskyapp/Tusky/issues/3429

---------

Co-authored-by: Zongle Wang <wangzongler@gmail.com>

app/src/main/java/com/keylesspalace/tusky/settings/AccountPreferenceDataStore.kt

@@ -3,8 +3,8 @@ package com.keylesspalace.tusky.settings
 import androidx.preference.PreferenceDataStore
 import com.keylesspalace.tusky.appstore.EventHub
 import com.keylesspalace.tusky.appstore.PreferenceChangedEvent
-import com.keylesspalace.tusky.db.AccountEntity
 import com.keylesspalace.tusky.db.AccountManager
+import com.keylesspalace.tusky.db.entity.AccountEntity
 import com.keylesspalace.tusky.di.ApplicationScope
 import javax.inject.Inject
 import kotlinx.coroutines.CoroutineScope

app/src/main/java/com/keylesspalace/tusky/settings/SettingsConstants.kt

@@ -62,13 +62,13 @@ object PrefKeys {
     const val READING_ORDER = "readingOrder"
     const val MAIN_NAV_POSITION = "mainNavPosition"
     const val HIDE_TOP_TOOLBAR = "hideTopToolbar"
+    const val SHOW_NOTIFICATIONS_FILTER = "showNotificationsFilter"
     const val ABSOLUTE_TIME_VIEW = "absoluteTimeView"
     const val SHOW_BOT_OVERLAY = "showBotOverlay"
     const val ANIMATE_GIF_AVATARS = "animateGifAvatars"
     const val USE_BLURHASH = "useBlurhash"
     const val SHOW_SELF_USERNAME = "showSelfUsername"
     const val SHOW_CARDS_IN_TIMELINES = "showCardsInTimelines"
-    const val SHOW_NOTIFICATIONS_FILTER = "showNotificationsFilter"
     const val CONFIRM_REBLOGS = "confirmReblogs"
     const val CONFIRM_FAVOURITES = "confirmFavourites"
     const val ENABLE_SWIPE_FOR_TABS = "enableSwipeForTabs"
@@ -111,9 +111,4 @@ object PrefKeys {
 
     /** UI text scaling factor, stored as float, 100 = 100% = no scaling */
     const val UI_TEXT_SCALE_RATIO = "uiTextScaleRatio"
-
-    /** Keys that are no longer used (e.g., the preference has been removed */
-    object Deprecated {
-        const val SHOW_NOTIFICATIONS_FILTER = "showNotificationsFilter"
-    }
 }