zephyr: print version number before boot

[toonst]

Before booting, It might be handy to see the version of the image we boot into.

[lorenzorubi-db]

@edurdevic same as PR #95 opened with my user latest commit takes care of your final comments thanks!

[lorenzorubi-db]

hi @edurdevic I still need to review further (and document better) but would like that you take a look so that we agree with the approach in the end the refactoring was much bigger to what I expected... anyhow now apply gives back a single dataframe with 3 boolean columns:

• rec_optimize with rows that need action with OPTIMIZE
• rec_vacuum analogous for VACUUM
• rec_misc other recommendations

plus 3 string columns with the reasons for each thanks!

[lorenzorubi-db]

@edurdevic ready to review, thanks

[lorenzorubi-db]

@edurdevic pls take another look, thanks