JSON enrollment importer v2 - part 1 - skip certain course types, use callingname, set is_rewarded correctly, and fix edit rights for contributors

[hansegucker]

Contains only smaller changes of #2500

[niklasmohrin]

Looks good; can you make the PR title and comment more descriptive so that we have something more to read in the Git history

[janno42]

Manually tested, seems to work :)

Small things you could fix here although they are from v1:

• Newlines between log entries are not consistent: For example after the "Name Changes" block there is no newline before "New Courses"
• Course names sometimes begin with whitespace in the log - the cleaned name should be shown instead.

[janno42]

Two more wishes: 🧞

• Replace all instances of continuous white space with a single space character (in all fields)
• types of exam events have changed. We now need to import exam events without a related non-exam event. In this case, their type is now the course type. They don't have a prefix in the title anymore.

[janno42]

✅ Functionality checked

There will be future changes but we can put that in v3 :)

[niklasmohrin]

looks mostly good, some comments:

[richardebeling]

lgtm if the open comments are resolved.

We have a few cases where a later commit overwrites a change of an earlier commit (formatting, narrower type annotation). Not to bad, if you want to rebase-merge we can do that, but I think squash-merge would also work (and clean that up)

[janno42]