Rename semver compare function

[wendellpiez]

As discussed in #3, now the namespace identifying functions serves across the repository, the name compare for the semantic versioning comparison function is too broad.

We agreed on semver-compare as the best balance between clarify and succinctness.

AC (please edit)

• the function is renamed
• any docs are changed accordingly

Dependency: some due diligence regarding if/where we use the function. Note: any callers have to change the namespace as well.

[galtm]

@wendellpiez or @aj-stein-nist : You can assign this to me. I can fix it in the next few days.