[RSB] Support deployment

[chrisj at rtems.org]

Hi,

These patches update the RSB to support deployment. With this change you can
create a directory anywhere and in it add a buildset file and build an RTEMS
vertical software stack. For example:

  mkdir project
  cd project
  mkdir config
  vi config/project.bset

And in the buildset file add:

  %define with_rtems_bsp aarch64/xilinx_versal_aiedge
  6/rtems-aarch64
  6/rtems-kernel

The changes:

- Clean up the kernel and BSP support in the RSB to better handle
  options and configurations

- Add better support kernel config.ini files

- Change bset tarfiles to package the staged files

- Use python's tarfile support

I have a new section for the User manual ready.

Once these patches are merged I will backport some to RTEMS 5 so deployment
can be supported in 5.2.

After that is completed I will reformat the RSB using yapf.

Chris