DynamicTablesPkg: Extract AcpiHelperLib from TableHelperLib

DynamicTablesPkg: Extract AcpiHelperLib from TableHelperLib

The TableHelperLib contains helper functions. Some rely on
DynamicTablesPkg definitions (they use Configuration Manager objects).
Some others are more generic.

To allow using these generic functions without including
DynamicTablesPkg definitions, move them to a new AcpiHelperLib
library.

Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>
Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com>