Add validate_fmf_id function

[thrix]

Introduced to tmt, but seems useful directly in fmf library.

Signed-off-by: Miroslav Vadkerti mvadkert@redhat.com

[thrix]

/packit test

[psss]

I find the mapping implementation a bit cryptic. It also requires all fmf id dictionary keys to be defined. I think several if/elif statements would make the code much more readable. Also one brainstorming idea: What about throwing exceptions upon errors and returning just True when everything is fine? Seems more natural than return (True, ''). Also this could be directly handled in Tree.node() and this extra function would not be necessary.

[thrix]

we decided to drop this