Support for deleting a subset of all conversation messages

Closes #1629

See merge request !1180

Always show keyboard when clicking text input field

Closes #1405

See merge request !1181

This also implements the method for MessagingManager
(including integration tests) and adds no-op implementations for other
clients.

Raise target API version to 28 and fix soft keyboard issues

Closes #1505

See merge request !1043

Update XML code style settings

See merge request !1178

Torsten Grote authored Mar 14, 2019 and akwizgran committed Oct 18, 2019

1. Manually request focus for input fields and show keyboard

This is needed when targetting API 28 which doesn't give focus anymore
automatically like it used to be.

Closes #1505

2. Remember keyboard states across screen rotations

This also upgrades the emoji library and gets rid of the
KeyboardAwareLinearLayout that is still a relict from the time when we
were using Signal's emoji implementation.

3. Move soft keyboard showing/hiding into UiUtils

Android Studio 3.5 changed our codeStyles

See merge request !1177

UX for handling duplicate handshake links

Closes #1565

See merge request !1173

[android] Fix duplicate items in lists

Closes #1210

See merge request !1174

When doing reloads of list items such as when adding test contacts,
we loaded different versions of those items and added them to the list.
According to the documentation
https://developer.android.com/reference/android/support/v7/util/SortedList.html#add
> If the sorting criteria of the item is changed,
> SortedList won't be able to find its duplicate in the list
> which will result in having a duplicate of the Item in the list.

For the contact list at least, new contacts caused reloads of the entire list
and new messages caused the contacts to be sorted differently.
Thus we ended up with duplicate contacts in the list.

This commit fixes this by replacing the contacts in the list instead of adding them.
It applies the same fix to forums and private groups
which use the same logic and are thus also affected.

Fixes #1210

If two different people sent the same link, show warning dialog to the
user to prevent a social attack trying to discover contact
relationships.