Go-Library: test and create version-strings

[JanHoefelmeyer]

As defined via https://docs.oasis-open.org/csaf/csaf/v2.0/os/csaf-v2.0-os.html#31232-branches-type---name-under-product-version-range.

The go-library should be able to test a string representing a version range for validity and create a valid version-range-representing string. This would e.g. allow it to be added to a document via the functions implemented in #561