Dell OS10 improvements

[jbemmel]

• Wait while system gives "loading" prompt
• Add note on qcow2 compression, reduced image to ~30% in my case for 10.5.6.6:
  -rw-r--r-- 1 jvanbemmel jvanbemmel 2336227328 Oct 31 08:54 dellftos.10.5.6.6.qcow2

More general changes:

• Refactor management IP network settings, make them configurable
• Change Dell OS10 management link to private 169.254.127.0/24 range, to minimize chance at overlap with other configs ( original 10.0.0.0/24 is way too common ... )
• Forward only the TCP ports used by the platform, not the full set of those used by all other platforms
• Address warnings caused by format strings to logger

[hellt]

Since #279 has been started, it would make sense to ensure that ftos works with the scrapli driver. The plan is to remove telnet scraping in a short while as it served its time

[jbemmel]

I’m fine with that, but can we accept this PR in the meantime until the ideal architecture is available?

OS10 is currently broken

[hellt]

@log1cb0mb, @ssasso, @nlgotz hi all, you have contributed to ftosv support in the past, since this PR is intrusive, would you care to try it out before it gets merged?

[jbemmel]

@log1cb0mb, @ssasso, @nlgotz hi all, you have contributed to ftosv support in the past, since this PR is intrusive, would you care to try it out before it gets merged?

I didn't intend to submit those more radical refactorings as part of this PR, guess I forgot to switch branches - sorry.
Happy to refactor and include just the "waiting for OS10" changes

[ssasso]

It is working on my machine! :) tnx @jbemmel for solving the annoying "loading" stuff.

[hellt]

thnx @ssasso and @jbemmel