Backend: Tables need to be converted to data frames

[fridgepoet]

What happened:
While enabling some old tests, we discovered there were some assertions on "Table" objects. These seem to have been deprecated in the past and converted already in Elasticsearch grafana/grafana#34710.

For example in this test

opensearch-datasource/pkg/opensearch/response_parser_test.go_

Line 531 in ed3bb92

So(queryRes.Tables, ShouldHaveLength, 1)

I expected that queryRes should have some Frames with the old data that was asserted in the Tables, but currently Frames is empty.

What you expected to happen:
The formerly-populated Tables object should be transferred to Frames. Every test that involves a Table should be updated and probably passing with the equivalent data.

How to reproduce it (as minimally and precisely as possible):

• Go to response_parser_test.go
• Enable a test that makes assertions with Tables
• Comment out everything after queryRes
• Inspect the the queryRes object, for example with a debugger
• It should probably have the formerly-asserted data in the data Frames

Environment:

• Plugin version: v2.4.1