Add Table.expand_to_rows to allow flattening vector and array values in table.

[jdunkerley]

Similar to expand_column, but in this case expanding "iterable" objects to a row per item.

• Repeat other columns.
• Old column name is preserved.
• Vector, Array and List each item becomes a row.
• Range and Date_Range should be materialized to rows.
• Single value stays as a single row (e.g. Nothing or Number).

Use a pattern similar to #7957 allowing us to add conversion and then expand would work.

[enso-bot]

Greg Travis reports a new STANDUP for today (2023-10-09):

Progress: tests + implementation It should be finished by 2023-10-11.

Next Day: builder that refuses to grow

[enso-bot]

Greg Travis reports a new STANDUP for today (2023-10-10):

Progress: builder bug It should be finished by 2023-10-11.

Next Day: test for fix, refactor

[enso-bot]

Greg Travis reports a new 🔴 DELAY for today (2023-10-11):

Summary: There is 1 day delay in implementation of the Add Table.expand_to_rows to allow flattening vector and array values in table. (#7959) task.
It will cause 0 days delay for the delivery of this weekly plan.

Delay Cause: builder bug

[enso-bot]

Greg Travis reports a new STANDUP for today (2023-10-11):

Progress: builder bug, tests for that, Pair, additional tests, move fan_out code to separate file It should be finished by 2023-10-12.

Next Day: rebase on Radek's, PR