ui: Non-circular overlays and less buttons

Part-of: <https://gitlab.gnome.org/GNOME/loupe/-/merge_requests/450>

Cargo.lock

@@ -1287,9 +1287,9 @@ dependencies = [
 
 [[package]]
 name = "libc"
-version = "0.2.155"
+version = "0.2.158"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "97b3888a4aecf77e811145cadf6eef5901f4782c53886191b2f693f24761847c"
+checksum = "d8adc4bb1803a324070e64a98ae98f38934d91957a99cfb3a43dcbc01bc56439"
 
 [[package]]
 name = "libgweather"
@@ -1388,6 +1388,7 @@ dependencies = [
  "indexmap",
  "kamadak-exif",
  "libadwaita",
+ "libc",
  "libgweather",
  "log",
  "once_cell",