Initial code import

This brings in code from our kirkstone-staging branch, excluding binary blobs of any kind, and cleaning history of any such IP violations.

Closes eclipse/oniro-core/oniro#265 (closed), eclipse/oniro-core/oniro#266 (closed), eclipse/oniro-core/oniro#390 (closed) and eclipse/oniro-core/meta-clang#2 (closed)

.gitlab-ci/container/bitbake-builder/ppa/zyga-ubuntu-oh-tools-focal.list

+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: 2020 Huawei Inc.
+deb https://ppa.launchpadcontent.net/zyga/oh-tools/ubuntu focal main
+#deb-src https://ppa.launchpadcontent.net/zyga/oh-tools/ubuntu focal main