These were found after running `codespell`.

(cherry picked from commit 679bab1b48a01d717dfdd2bb9b631b18268fdce1)

* Move to the `data` subfolder
* Update the maintainer
* Use a slightly saner indentation

libhandy has reached a stable point, so distributions should start
including it as a proper package rather than relying on a git submodule.

This also fixes some small annoyances in the build system.

Put the JUnit helper functions in a separate script and make them more
generic.

This commit removes all remaining occurrences `using Gtk;`, `using Gee;`
and `using Hdy;`. There's a number of reasons why we're doing this, but
to list a few:

* The `Gtk` and `Hdy` namespaces have had issues before with types
  having the same name (ie HdyHeaderBar and GtkHeaderBar) which could
  suddenly break the build.
* By omitting namespaces, it's harder to see for new contributors what
  the actual type is of a certain variable when they want to look up the
  API
* In the long term, we want to get rid of Gee, as it's clear that it's
  not really maintained, and has some serious performance drawbacks.

Google+ is dead, so let's not waste maintenance and performance on it.

The Flatpak build has several issues when there is a version mismatch
between the build E-D-S and the host E-D-S, so we have a recurrent wave
of people saying Contacts is broken everytime we release a new version.

I'm not sure what to do with the flatpak build yet, but let's not
advertise it in our README.

It's outdated, and in general something we couldn't remove while we
still had an autotools-based build. But we're 2020 now, so let's get rid
of it.

`do` is a keyword, so it confuses some tooling.

Fixes https://gitlab.gnome.org/GNOME/gnome-contacts/-/issues/129

To implement search-as-you-type, we make sure to focus the search field
if that wasn't the case already. However, if a user types something wile
Contacts is still starting up, the UI hasn't finished by that time
already, so that will lead us to dereferencing a NULL-pointer.

To fix this nice and easy, let's to do a quick NULL-check before we try
to focus anything.

Fixes: https://gitlab.gnome.org/GNOME/gnome-contacts/-/issues/155

This will allow the app to be available in Phosh and PureOS Store.

In a lot of places, we're accidentally taking a strong reference to a
variable, which means that internally, we'll be using a lot of
`g_object_ref()` and `g_object_unref()` for no good reason. Especially
on some hot paths (and large address books), this can make a tiny bit of
a difference in terms of performance.

It's happened already that some things clash with the Handy namespace,
so don't use `using Gtk;`.

We don't have our own `Contact` class anymore, only `Folks.Individual`
is used now.

And don't use `using Gtk;`, since some names of types can clash.

* Use the gitlab.gnome.org libhandy repo
* Disable unused libhandy options
* Make GOA requirement for librest explicit
* Some formatting

Fixes https://gitlab.gnome.org/GNOME/gnome-contacts/-/issues/188

When switching to libhandy 1.0, we accidentally broke the valadoc build,
since that tried looking for the `handy 0.0` package. Fix the custom
target to look for the correct one now.

Fixes https://gitlab.gnome.org/GNOME/gnome-contacts/-/issues/177

ContactsEditorProperty: Make sure the Postal Address EditorPropertyRow "is_empty" value is properly set

Allows us to drop the use of HdyTitleBar.

(cherry picked from commit befccbd1)

(cherry picked from commit 6ab24327)

Makes Contacts.Avatar a wrapper around HdyAvatar.
This allows us to drop our custom fallback and
circular avatar code in favor of HdyAvatar.

Fixes https://gitlab.gnome.org/GNOME/gnome-contacts/-/issues/183

Related to https://gitlab.gnome.org/GNOME/Initiatives/-/issues/20