Use createOrUpdate in importlib & REST interface

[bruno]

This issue is a split-off from #156.

Quoting from there: "using the createOrUpdate method in the import library (and hence REST itf). This is not entirely straightforward since that currently has the notion of 'is already up to date', we should see if this can be known and returned in the HBaseRepository too (most likely yes: see returned boolean of calculateRecordChanges)."

And related to it: "supporting createOrUpdate for the non-record entities (the schema entities: field type and record type)"

[bruno]

In [4803]:

importlib: make use of Repository.createOrUpdate in RecordImport? (makes this class mostly unnecessary, but leaving it in place until we do the same for the schema). Fixes #227.