Skip error.stack_trace if empty

[mosche]

Opening this PR for discussion.

Some exceptions in Elasticsearch don't contain a stacktrace, e.g. NotMasterException.
For these error.stack_trace typically just repeats what's already present in error.type and error.message, having the field doesn't add any value.

Can we skip error.stack_trace in this case?

[JonasKunz]

Hey @mosche , sorry for the delayed response.

For these error.stack_trace typically just repeats what's already present in error.type and error.message, having the field doesn't add any value

This feels like a very elasticsearch specific edge-case, therefore I'm not sure whether we want to add this.
I also think that in general this would lead to a worse user-experience: E.g. if one is filtering on specifically error.stack_trace to contain a word, those errors would suddenly not match the search anymore, which isn't intuitive without knowledge of this "feature".