Merge aria-description/aria-colindextext/aria-rowindextext IDL tests in aria-reflection.tentative.html into aria-attribute-reflection.html (supported by 3 implementations)

[rahimabdi]

I believe the tentative reflection tests for aria-description, aria-colindextext, aria-rowindextext can be merged into aria-attribute-reflection.html once the WPT Safari test results are "PASS".

The outstanding failures are for aria-colindextext and aria-rowindextext for WebKit, and this was recently patched: WebKit/WebKit#48864.