Add TSV support

[philrz]

Once brimdata/super#4891 merges, we can add TSV as an import/export format in Zui both as a feature and something to test via CI.

[philrz]

Verified in Zui commit e9c7753.

Similar to the verifications of the Zed-level TSV support in brimdata/super#4746 (comment), the attached video shows load of TSV data taken from Google Sheets. Once it's loaded into Zed format via Zui, it's then Exported back out as TSV.

Verify.mp4

To further improve on this workflow, we may look at allowing paste directly into Zui (#2909).