ref(explorer): clean up old trace rpcs and auto-select sort field

[aliu39]

• Cleans up the trace rpcs which are no longer called (replaced by table_query and timeseries_query).
• Guards against a common snuba gotcha where the sort field must be present in selected fields. Fixes SEER-6GE
• Return only the table data and not the meta, which is unused
• Some test renaming and adds a very basic logs sanity check test