Tabular formatting

[lionel-]

A comment like # fmt: tabular would instruct Air to format the next expression (which should be a function call) with these rules:

• The first line of arguments determines the number of columns
• The remaining arguments are wrapped according to the number of columns
• Arguments are aligned at commas

This would help with tribble-like data entry but could also be used with list() or c() depending on the use case.

Difficulties:

• Investigate how to hook into Biome's infra to add this special formatting

• The formatter may move comments around if they are in peculiar cases, and then a second round of formatting might cause the tabular comment to apply to something else. That's undesirable because we generally want the formatter to be idempotent.