Implemented more tests, added "view spoilers" feature

app/build.gradle.kts

app/src/main/java/de/kuschku/quasseldroid/Quasseldroid.kt

...uschku/quasseldroid/service/QuasselNotificationBackend.kt

...chku/quasseldroid/ui/chat/messages/MessageListFragment.kt

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

.../kuschku/quasseldroid/util/irc/format/ContentFormatter.kt

...hku/quasseldroid/util/irc/format/IrcFormatDeserializer.kt

...sseldroid/util/irc/format/spans/IrcBackgroundColorSpan.kt

...kuschku/quasseldroid/util/irc/format/spans/IrcBoldSpan.kt

...sseldroid/util/irc/format/spans/IrcForegroundColorSpan.kt

...schku/quasseldroid/util/irc/format/spans/IrcItalicSpan.kt

...ku/quasseldroid/util/irc/format/spans/IrcMonospaceSpan.kt

...uasseldroid/util/irc/format/spans/IrcStrikethroughSpan.kt

...ku/quasseldroid/util/irc/format/spans/IrcUnderlineSpan.kt

...src/test/java/de/kuschku/quasseldroid/QuasseldroidTest.kt

...quasseldroid/util/irc/format/IrcFormatDeserializerTest.kt

gradle.properties