Description

The adding blocks test has been failing recently at the test it inserts blocks at root level when using the root appender while selection is in an inner block.

The image snapshot for this failure shows that the test makes it almost all the way to the end but fails to add a paragraph block from the quick inserter menu:

When manually testing it's noticable that the patterns in the menu have a slight delay in loading their content causing a shift in the layout in the inserter. I think what's happening is that the layout shift is causing the test to fail to click on the block. When the popover is above the button this is particularly difficult, because everything above the patterns shift up and down.

This PR should fix by doing the following:

• Most of the time the paragraph block doesn't actually need to be searched for. If it's immediately shown in the menu the test now adds the block without searching, bypassing the layout issue.
• If the block does need to be searched for I've added a waitForInserterPatternLoad helper function that waits for all the patterns to have a height greater than zero. I couldn't think of a better option here, I think the best idea would be to look at improving the way patterns load

Types of changes

Bug fix (non-breaking change which fixes an issue)

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR.