rng-tools: Move from core package to addon - fixes bug 12900

rng-tools: Move from core package to addon - fixes bug 12900

- This patch is to move the rng-tools package from a core package to an addon. With the
   kernel changes from 5.6 rngd is no longer needed to create the required kernel entropy.
- The results from HRNG's via rngd are used with an XOR after the entropy is
   collected by the kernel. So the HWRNG output is used to dilute the kernel random number
   data, which is already merged from several sources.
- Based on the above and @Paul's request in the bug report to have rng-tools kept as an
   addon this patch set is submitted for consideration to keep rng-tools but as an addon.
- move rng-tools rootfile from common to packages
- Modify rng-tools lfs from core package to addon package
- Create rng-tools pak to install and uninstall - creating rc.d links for start & stop.
- Move rngd initscript from system to packages directory.
- Installed into my vm testbed and confirmed that it works. No rngd daemon installed
   from iso install. After addon install rngd is present and running. Added various files
   to be able to test the services wui page. rngd shows up and can be turned off and on

Fixes: Bug#12900
Tested-by: Adolf Belka <adolf.belka@ipfire.org>
Signed-off-by: Adolf Belka <adolf.belka@ipfire.org>
Reviewed-by: Bernhard Bitsch <bbitsch@ipfire.org>