Release gnome-online-accounts 3.49.2

See merge request GNOME/gnome-online-accounts!170

Strange things happens with close-request and our dialog's state machine
if we try to make a chain of transient modals. Instead, become a
transient of the real root window, in the rare case a provider subclass
needs to chain-up to a parent's dialog.

Partially addresses #295

We no longer return a GtkDropDown, and in fact only guarantee an
object with the property "selected". Use `g_object_set()` instead.

This is a relic from a time when the provider had multiple pages.

goabackend: Insist on being a transient of the real root

See merge request GNOME/gnome-online-accounts!174

.desktop: Add trailing newline

See merge request GNOME/gnome-online-accounts!177

goabackend: fix defunct call to GtkDropDown method

See merge request GNOME/gnome-online-accounts!176

Drop all expander rows in favour of regular groups.

closes #297

The only reason to subclass the WebDAV provider is to brand it for
a specific implementation, in which case we leave the burden of
custom endpoints to the derived provider and hide the UI.

Note that we already have custom checks for ownCloud/Nextcloud,
the only extant branded subclass.

Split the server entry row from the username/password pair, such that
there's room for a descriptive example.

Add a `description` argument to `goa_provider_dialog_add_page()`,
so providers can give context for a service.

For each provider with setup dialog, add a page-level description of
the service of the service.

closes #296

Providers will want to add descriptive hints for some fields, so add
a convenience method to add a dimmed label to the current group,
with the option to set the accessible target.

For each provider, add a descriptive label to indicate when server
settings may be automatically detected and valid example for
ambiguous fields.

The Kerberos provider defers to a system dialog for password entry,
so use "Sign in…" in the button's label.

The MS365 provider defers to the parent OAuth dialog for authentication,
so use "Sign in…" in the button's label.

Update the remaining labels in setup dialogs to those in the current
design for GNOME 46.

Remove the height-request and set the larger, IMAP/SMTP setup
dialog to 600px in height.

goabackend: update UI and strings to GNOME 46 design

Closes #296 and #297

See merge request GNOME/gnome-online-accounts!178

closes #299

Fix spelling typo

Closes #299

See merge request GNOME/gnome-online-accounts!179

goabackend(ms_graph): fix typo

See merge request GNOME/gnome-online-accounts!180

The last call to it was dropped in commit
c0a50256.

Signed-off-by: Philip Withnall <pwithnall@gnome.org>

goabackend: Drop unused function

See merge request GNOME/gnome-online-accounts!181

The `goabackend` has been ported to GTK this cycle, and also
includes several API breaks for account setup.

This will affect downstream projects relying on the dialogs and
functions called from GNOME Settings forks.

Bump the GoaBackend .so version to 2.0.0

Closes #291

See merge request GNOME/gnome-online-accounts!182