mepo status and compare can show differences when there aren't

[mathomp4]

The issue is that mepo gets "where are we" by running a git command that responds in odd ways.

To wit, say in components.yaml you say you want GOCART v1.0.0. When you mepo clone:

❯ mepo clone
Found style [naked] in .mepoconfig
Initializing mepo using components.yaml with naked style.
env                    | (t) v3.2.1
cmake                  | (t) v3.4.2
...
GOCART                 | (t) v1.0.0
mom                    | (t) geos/5.1.0+1.1.1
...

Hey, you got GOCART v1.0.0!

Now if you immediately run mepo status:

❯ mepo status
Checking status...
GEOSgcm                | (b) main
...
GOCART                 | (t) v1.0.0-beta.1 (DH)
...

Different tag and "GOCART" will be in red, but nothing is different. The reason is that commit in GOCART is tagged with two tags. mepo compare does the same thing:

❯ mepo compare
Repo                   | Original                         | Current
---------------------- | -------------------------------- | -------
GEOSgcm                | (b) main                         | (b) main
...
GOCART                 | (t) v1.0.0 (DH)                  | (t) v1.0.0-beta.1 (DH)
...

This is because mepo gets this information from:

❯ git show -s --pretty=%D HEAD
HEAD, tag: v1.0.0-beta.1, tag: v1.0.0

and it then uses the first tag. I think it's in some weird reverse alphanumeric order? Still, it seems almost random at times!

This should be fixable.