Inconsistent SpanIDs and TraceIDs in span links

[mabdinur]

Test agent produces snapshot files with normalized span_ids and trace_ids. However this normalization is not applied to span ids and trace ids in span_links. This hinders the reproducibility of snapshot tests (test runs that generate different span ids will generate different snapshots).

A simple fix would be to add span_links and meta._dd.spans_links to DEFAULT_SNAPSHOT_IGNORES. However it would be nice to actually validate span_link values in snapshot tests.

There are two scenarios we need to handle:

• All span links reference spans that are received by the test agent (here we can neatly normalize all ids)
• Some span links reference span/trace ids that are NOT received by the test agent. This scenario is a bit tricky. The best we could potentially do here is set some "catch_all" value.