image: Add locale archive optimisation

image: Add locale archive optimisation

Refactor the locale archive function from the SDK to also make it work during
general image creation. This reduces the size of the locales from 900MB to 220MB
in core-image-lsb-sdk.

The exception handling around subprocess was dropped as the standard subprocess
exception printing is better handled than the catchall exception.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>