Handle IM (Jabber) "add to contact" intent URI

[ltguillaume]

Checklist

• I can reproduce the bug with the latest version given here.
• I made sure that there are no existing issues - open or closed - to which I could contribute my information.
• I made sure that there are no existing discussions - open or closed - to which I could contribute my information.
• I have read the FAQs inside the app (Menu -> About -> FAQs) and my problem isn't listed.
• I have taken the time to fill in all the required details. I understand that the bug report will be dismissed otherwise.
• This issue contains only one bug.
• I have read and understood the contribution guidelines.

Affected app version

1.5.0

Affected Android/Custom ROM version

Any

Affected device model

Any

How did you install the app?

F-Droid / IzzyOnDroid

Steps to reproduce the bug

1. Open a Conversations-based XMPP client (e.g. Conversations, Cheogram, monocles chat)
2. Open a contact's details and choose "Save to contacts" (or click on the avatar if that button isn't present)
3. Choose a contact to add the IM Jabber (=XMPP) field to
4. See that no IM field is filled in

Expected behavior

Handle the intent by the XMPP client properly and add the IM field to the selected contact.

Actual behavior

Nothing is added to the selected contact.

Screenshots/Screen recordings

No response

Additional information

The exact intent URI as sent by the XMPP client is as follows

intent:#Intent;action=android.intent.action.INSERT_OR_EDIT;type=vnd.android.cursor.item/contact;launchFlags=0x3000000;extendedLaunchFlags=0x4;B.finishActivityOnSaveCompleted=true;i.im_protocol=7;S.im_handle=user%40server.tld;end

where im_protocol=7 means the Jabber IM field and user@server.tld is the value.