[Fix] no-unknown-property: do not check fbs elements

[brian-ogilvie]

Currently <fbs> nodes are tagged with this linter warning:

Unknown property 'desc' foundNuclide-ESLint[react/no-unknown-property](https://www.internalfb.com/intern/bunny?q%3Deslint%2Breact%2Fno-unknown-property)

<fbt> nodes are already exempt from this lint rule, and <fbs> should be treated the same.

Internal WP discussion: https://fb.workplace.com/groups/eslintfeedback/permalink/6064426636924059/

[codecov]

Codecov Report

Merging #3494 (5506881) into master (c6d082a) will not change coverage.
The diff coverage is 100.00%.

❗ Current head 5506881 differs from pull request most recent head 54c56a1. Consider uploading reports for the commit 54c56a1 to get more accurate results

@@           Coverage Diff           @@
##           master    #3494   +/-   ##
=======================================
  Coverage   97.57%   97.57%           
=======================================
  Files         129      129           
  Lines        9200     9200           
  Branches     3336     3336           
=======================================
  Hits         8977     8977           
  Misses        223      223           

Impacted Files	Coverage Δ
lib/rules/no-unknown-property.js	98.82% <100.00%> (ø)

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

[ljharb]

oof, i had no idea there were two of these. is that an exhaustive list? (i can't view the workplacae discussion, obv)

This is good to go as soon as we can add a test using fbs.

[brian-ogilvie]

Yeah, fbs has basically the same api as fbt, but it returns the pure string result instead of a node. This is useful for things that really need to be string for a18y purposes like the an aria-label, etc.

I'll add a test

[ljharb]

Thanks! I'll try to get another patch out in the next day or three.