Edit to Test 18.B in web

[KMSOC]

Description
To match the logic in the software baseline, consider modifying Test 18.B so that there is only one test:

1. Check that the reading order and meaning of the content (in context) is correct without the CSS position property. [SC 1.3.2]

Which Baseline
To help us address your issue more effectively, please identify which Baseline has the issue:

• Web

[kengdoj]

Test 18 in both Docs and Web should have the same name, if possible.

[kengdoj]

For web baseline, ensure reading order of modal is covered.