[re #12346] Saving of BasicRoles into roles table

Created a prototype of saving first roles into the SPADe table role. Right now, we only save that BasicProjetRole, because that's the only available object we can fetch yet (when I tried multiple times - via browsers or even the code - other objects, i always got 401 error even thought we are authorized)... So I will make notes to Mr. Pícha and will discuss that with him during next session/questiong that Jakub Pavlíček (a.k.a. John Pork) sends him weekly.

TLDR:

• Added support of saving and mapping BasicProjectRole domain objects into role table (not linked with person yet - we do not know how)
• Added support for saving users in comment section as well - we should be able to save (after that) all users (not only reportes and assignees)
• Added a few documentation comments

POV (Easter egg since there are Easter): Me when I got for the last 2-3 hours 401 errors from Jira API: