dillon1000/react

Add warning if rendering and HTMLUnknownElement (#9163)

* Add warning if rendering and HTMLUnknownElement

* Records fiber tests

* Fixes linting and server render tests

* Incorporates review comments

* Uses ownerDocument instead of document

* uses el instead of creating a new element

* Removes warning check of voidElementTags

* Add missing space to unknown element warning

* Only call isCustomComponent once

* Spy on console in menuitem test

Since menuitem is treated as an unknown element in jsdom it triggers the unknown element warning.

* Add unknown element warning to Fiber

* Replace instanceof with toString check

It is more resilient.

* Record tests