Offer query plan capability

[bourette]

Issue Type: Feature Request

It would be nice to be able to get the query plan like SMP. Very useful in development.

Extension version: 0.1.0
VS Code version: Code 1.51.0 (fcac248b077b55bae4ba5bab613fd6e9156c2f0c, 2020-11-05T18:14:40.758Z)
OS version: Darwin x64 19.6.0

[bdeboe]

You can use EXPLAIN to get the query plan in its usual pseudo-XML form today, but there's a lot of opportunity to make that look prettier.

I'd say a reasonable short-term enhancement would be to

• make the current query plan output from EXPLAIN display as multiline like it does on an IRIS console (might be me on windows?)
• add a button to get the query plan for the current query, either at the top of the script widget (like "run on active connection") or the bottom of the results widget (like "re-run query", "export", ...)

Within IRIS SQL, we're planning some enhancements to how query plans are returned that should make them easier to interpret by code and visualize.