Fix flaky tab writing behavior using text/tabwriter

[bschaatsbergen]

Alternative implementation to #19

Background

This prototype addresses the flaky tab writing issues caused by relying on a regular os.File writer along with our existing tab-based formatting. The output is now handled by a tabwriter.Writer from the text/tabwriter package, which integrates with the existing view/stream mechanism as it implements the io.Writer interface too. The tabwriter package acts as a write filter, translating tabbed input columns into proper aligned text for consistent and reliable formatting.

Debugging

In 1727fac, I added support for debugging the tab writer. When the debug flag is set, it prints a vertical bar ('|') between columns after formatting, and any discarded columns appear as zero-width columns ("||").

A      |example.com.   |37m46s      |93.184.215.14
NS     |example.com.   |21h17m02s   |a.iana-servers.net.
NS     |example.com.   |21h17m02s   |b.iana-servers.net.
SOA    |example.com.   |01h00m00s   |ns.icann.org. noc.dns.icann.org.
MX     |example.com.   |21h47m50s   |0 .
TXT    |example.com.   |21h25m07s   |v=spf1 -all
TXT    |example.com.   |21h25m07s   |wgyf8z8cgvm2qmxpnbnldrcltvk4xqfn
AAAA   |example.com.   |18m57s      |2606:2800:21f:cb07:6820:80da:af6b:8b2c

To be considered

FWIW, it might be worth considering moving the tab writer implementation down into the rendering logic, as this would make sure that consumers (e.g., tests) inherit all the behavior of the tab writer. On the other hand, the rendering logic is designed to support any writer, so this change might compromise that flexibility.