Added sectioned fastscrolling to nick and buffer lists

app/build.gradle.kts

...kuschku/quasseldroid/ui/chat/buffers/BufferListAdapter.kt

...u/quasseldroid/ui/chat/messages/QuasselMessageRenderer.kt

.../de/kuschku/quasseldroid/ui/chat/nicks/NickListAdapter.kt

...de/kuschku/quasseldroid/ui/chat/nicks/NickListFragment.kt

...ava/de/kuschku/quasseldroid/util/ui/DrawerRecyclerView.kt

app/src/main/res/layout/fragment_chat_list.xml

app/src/main/res/layout/fragment_nick_list.xml

...ava/de/kuschku/quasseldroid/viewmodel/data/IrcUserItem.kt