packagegroup-allscenarios-core: Introduce core packagegroup

Currently, it only includes x-mounts.

Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>

meta-ohos-core/recipes-core/packagegroups/packagegroup-allscenarios-core.bb

+# SPDX-FileCopyrightText: Huawei Inc.
+#
+# SPDX-License-Identifier: Apache-2.0
+
+DESCRIPTION = "Core package group groups for OS foundation"
+
+inherit packagegroup
+
+PACKAGES = "packagegroup-allscenarios-core"
+
+RDEPENDS_packagegroup-allscenarios-core = "\
+	x-mounts \
+	"