Easily allow ignoring users from the context menu

...seldroid/ui/coresettings/ignoreitem/IgnoreItemActivity.kt

...seldroid/ui/coresettings/ignoreitem/IgnoreItemFragment.kt

...seldroid/ui/coresettings/ignorelist/IgnoreListActivity.kt

...seldroid/ui/coresettings/ignorelist/IgnoreListFragment.kt

.../de/kuschku/quasseldroid/ui/info/user/UserInfoFragment.kt

...java/de/kuschku/quasseldroid/util/avatars/AvatarHelper.kt

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

...ain/java/de/kuschku/libquassel/util/irc/HostmaskHelper.kt

...java/de/kuschku/libquassel/util/irc/HostmaskHelperTest.kt