subprojects: Add libcall-ui as meson subproject

Get rid of the git submodule and forward to the latest commit
that avoids deprecation warnings while we're at it.

Signed-off-by: Evangelos Ribeiro Tzaras <devrtz@fortysixandtwo.eu>
Part-of: <https://gitlab.gnome.org/GNOME/calls/-/merge_requests/806>

.gitignore

@@ -8,5 +8,6 @@ _build
 .flatpak-builder
 .gdb_history
 subprojects/.wraplock
+subprojects/libcall-ui
 po/calls.pot
 po/missing

.gitmodules

@@ -1,3 +0,0 @@
-[submodule "subprojects/libcall-ui"]
-	path = subprojects/libcall-ui
-	url = https://gitlab.gnome.org/World/Phosh/libcall-ui.git

subprojects/libcall-ui.wrap

@@ -0,0 +1,5 @@
+[wrap-git]
+directory=libcall-ui
+url=https://gitlab.gnome.org/World/Phosh/libcall-ui.git
+revision=3a2044f8e7c45387954ed35d22c6b6309e6751d6
+depth=1