Show the follower's bio/note in a "followed you" notification (#3281)

This makes the notification view for a follow request contain more info about the new follower, and makes the layout (of their name / username) consistent with other notifications that show names/usernames.

app/src/test/java/com/keylesspalace/tusky/BottomSheetActivityTest.kt

@@ -56,6 +56,7 @@ class BottomSheetActivityTest {
         localUsername = "admin",
         username = "admin",
         displayName = "Ad Min",
+        note = "This is their bio",
         url = "http://mastodon.foo.bar/@User",
         avatar = ""
     )