move base64.h to sys/base64.h and
create a shim for backward-compatibility.
No functional changes to the headers.
A warning in the shim can be controlled with CONFIG_COMPAT_INCLUDES.
Related to #16539
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
As per the Apache v2 License, state changes made to the original code in
the modified version of the files.
Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>
