[FEAT] connect: explain (WIP)

[andrewgazelka]

we should figure out how we want .explain to output

should it include

• logical plan
• optimized logical plan
• physical plan

etc? and if so how

[andrewgazelka]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• [FEAT] connect: explain (WIP) #3379 👈 (View in Graphite)
• feat(connect): add df.{intersection,union} #3373 : 2 other dependent PRs (#3375 , #3384 )
• [CHORE] connect, test: df.withColumn #3359
• [FEAT] connect: add modulus operator and withColumns support #3351
• [FEAT] connect: add binary operators #3350 : 3 other dependent PRs (#3346 , #3376 , #3387 )
• [FEAT] connect: support basic column operations #3362 : 1 other dependent PR (#3363 )
• [FEAT] connect: to_daft_* use ref instead of value #3355 : 2 other dependent PRs (#3357 , #3360 )
• [FEAT] connect: add alias support #3342 : 6 other dependent PRs (#3344 , #3345 , #3348 and 3 others)
• [FEAT] consolidate Spark session fixture into conftest.py #3341 : 3 other dependent PRs (#3309 , #3326 , #3343 )
• main

This stack of pull requests is managed by Graphite. Learn more about stacking.