[SLE15-SP6] Install plain SLES instead of SLE_HPC (jsc#PED-7841)

[lslezak]

Problem

• The HPC product (+ the HPC module) will be replaced by plain SLES + HPC module in SP6
• https://jira.suse.com/browse/PED-7841
• When the AutoYaST XML profile requests installing the SLE_HPC then it would display an error:
  

Note: The HPC product is still defined in the latest ISO. For testing I used a manually tweaked installation repository with removed /Product-HPC directory and updated /media.1/products file.

Comments

• If this change was in SLE15 -> SLE16 (or SLE12 -> SLE15) I'd avoid adding hacks to YaST and prefer to solve that on the documentation level and in the release notes.
• On the other hand we should not break the SP6 installations with profiles that worked fine in SP5 and earlier. That would be a nasty surprise for the users.
• This allows using the same AY profile for both SP5 and SP6, less maintenance for users
• Note: Technically the HPC product is actually a SLES, the only difference is in the installed *-release package. (Plus HPC by default selects the HPC module.)

Testing

• Tested manually, now the AutoYaST installs the standard SLES and does not report any error
  

[coveralls]

coverage: 68.713% (+0.02%) from 68.693%
when pulling 6cdaec0 on HPC_SP6
into 1edbaf5 on SLE-15-SP6.

[yast-bot]

✔️ Internal Jenkins job #3 successfully finished
✔️ Created IBS submit request #321650