treewide: make code compie on clang

This patch fixed several minor issues that clang14 complains about.

1. clang-diagnostic-inconsistent-missing-override
2. clang-diagnostic-defaulted-function-deleted
3. clang-diagnostic-unused-const-variable

Tested:
1. it builds with clang14
2. tested on hardware, ldap config daemon and user manager daemon are
both good. Tested DBus APIs (e.g., create config) as well.

Signed-off-by: Nan Zhou <nanzhoumails@gmail.com>
Change-Id: Idf8d0481fc05735b4b3d021f30aa44272f2369bf
6 files changed