ESMValTool should have a --version option

[jfrost-mo]

Is your feature request related to a problem? Please describe.

While ESMValTool has the esmvaltool version command, the somewhat standard esmvaltool --version flag doesn't work. This should be added.

Also in the help text describing the version command the word conform is used incorrectly. (split into #3383)

version
-       Show versions of all packages that conform ESMValTool.
+       Show versions of all packages that form ESMValTool.

Would you be able to help out?

Yes, and this would be a good way to get familar with the codebase. I'll try and do it today.

[jfrost-mo]

Due to the way fire works, it appears this is actually rather hard. I'll split out the spelling correction into another issue and PR it for now. I'll have another look at the --version option later.

[valeriupredoi]

indeed - this is all due to Fire - I tried get this done myself many moons ago, and also get the shortop -V but it's a bit of a drag TBF 👍

[jfrost-mo]

There seems to be wider interest for this in Fire (google/python-fire#468) so maybe fixing it upstream is the right way. The project isn't hugely active however, so it would probably require implementing it ourselves.