Lnav unreasonably slow for long CSV string log.

[alabamagan]

lnav version
v0.12.2

Describe the bug
lnav becomes laggy when moving through long low strings. By "Long", I just mean csv with ~ 1000 elements > 50 lines. If the message spans across one page, lnav because unusable and will crash. Also, error traceback on python written by rich's log handler also tends to cause this problem. Sometimes it just crashes.

I think it's quite likely that logline field discovery is causing this issue, or perhaps the color codes written by rich have something to do with it.

To Reproduce
Steps to reproduce the behavior:
Try this log file:
rAIdiologist_2024-10-25.log

[tstack]

Took a quick look and it seems related to lots of ANSI escape sequences in a single log message. I'll look into trying to optimize it. Thanks for the report!