Support dot graph output in explain (analyze)

**Is your feature request related to a problem or challenge? Please describe what you are trying to do.**
We support converting a logical plan to a dot language graph (.dot) - I believe Ballista also supports it (by @andygrove ?) It would be great to support this as format for `explain analyze`

**Describe the solution you'd like**
Return the .dot graph output when giving the `FORMAT DOT` as option to explain / explain analyze statements. Amazon Athena has a similar feature: https://docs.aws.amazon.com/athena/latest/ug/athena-explain-statement.html

**Describe alternatives you've considered**

**Additional context**