NXCALS-3942 Smoother Exception handling

Merge request template

Even though the change looks scary, it is mostly backwards compatible

Existing users will be deserializing the new exceptions as string, so the content will be slightly different (curly braces, double-quotes etc.) but it will not crash and the message + stacktrace will still be there.

COMPATIBILITY NOTE

Please make sure that this change is BACKWARDS COMPATIBLE and a new server will work correctly with clients using old APIs versions.

It may be that data sent in the new format will break the old clients.

In case of any potential incompatibility we have to inform our clients and schedule release & deployment with them.

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@acc-logging-team - please have a look for approval.

Please describe the merge request here.

Closes NXCALS-3942