Forward-merge Xenial branch, November 2022

Merge changes made in xenial branch until November 2022.

Included in this MR:

• Failed MMS redownload (GitHub #260, !260 (closed))
• Fix startup crash (GitHub #310, !310 (closed))
• fix selecting a contact from the contact list (GitHub #315)
• display full image (GitHub #317)
• Re-enable Swipe Demo (GitHub #301, !301 (closed))
• Do not hardcode backend name (GitHub #320)
• Allow to display chars ( &, <, > ) (GitHub #333)
• Add a confirmation popup on Thread delete action (GitHub #334)
• Do not display attachments icons when MMS is disabled (GitHub #337)
• MMS error string fixes (GitHub #324)
• fix '&' chars in messages (GitHub #341)
• Fix error on property enableAttachments reading (GitHub #342)
• add sms to protocol (GitHub #281, !281 (closed)))
• fix urldispatcher (GitHub #346)
• debian: allow building with crossbuilder (GitHub #249)
• Issue 347: open contact for editing (GitHub #348)
• debian: bump dependency to apparmor-easyprof-ubuntu (GitHub #352)
• tests: export a HOME for the MessagesView test (GitHub #353)
• Revert "new contact backend" (GitHub #357)

Also included is a bunch of Weblate translations, and a small amount of manual renaming.