Add packagegroup cinnamon-session with what we have so far

Signed-off-by: Andreas Müller <schnitzeltony@gmail.com>

recipes-support/packagegroups/cinnamon-session.bb

@@ -0,0 +1,19 @@
+SUMMARY = "Basic Cinnamon desktop session"
+LICENSE = "MIT"
+LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda2f7b4f302"
+
+# at least cinnamon-menus are dynamically renamed
+PACKAGE_ARCH = "${TUNE_PKGARCH}"
+
+inherit packagegroup
+
+RDEPENDS:${PN} = " \
+    cinnamon \
+    cinnamon-desktop \
+    cinnamon-menus \
+    cinnamon-settings-daemon \
+    cjs \
+    muffin \
+    python3-xapp \
+    libxapp \
+"