Port mIRC Color handling from -NG

...ava/de/kuschku/quasseldroid_ng/util/helper/ThemeHelper.kt

.../quasseldroid_ng/util/irc/format/IrcFormatDeserializer.kt

...ku/quasseldroid_ng/util/irc/format/IrcFormatSerializer.kt

...kuschku/quasseldroid_ng/util/irc/format/spans/Copyable.kt

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

...chku/quasseldroid_ng/util/irc/format/spans/IrcBoldSpan.kt

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

...ku/quasseldroid_ng/util/irc/format/spans/IrcItalicSpan.kt

...quasseldroid_ng/util/irc/format/spans/IrcUnderlineSpan.kt