fix: consistent ClientID assignment, close #470

[localnerve]

What does this PR do?

• Fixes #470, make ClientID assignment consistent. Keeps the old policy, but if osClientID is there and different, use and update.
• Fixes the testSuite to execute without crashing after prior API updates that result in correct err and nil responses (see test suite for updates, pretty minor, but necessary to keep test suite functional).

Which issue(s) does this PR fix?

#470

If this PR affects any API reference documentation, please share the updated endpoint references

No change