Fix for bug with toggling opensInNewWindow state

[glendaviesnz]

Description

Currently the opensInNewWindow state is not toggled in InlineLinkUI if both the activeAttributes.url and activeAttributes.target props both change - in this case only the url change is reflected in the component state due to getDerivedStateFromProps returning before the opensInNewWindow check is hit

How has this been tested?

Tested manually as follows:

• Apply this patch to your local gutenberg dev env
• From a post/page editor, create a paragraph block
• Add a link
• Set the link to open in a new tab
• Click anywhere else
• Click the link -> settings , the “open in a new tab” should still be toggled on
• Save the page/post and reload the editor
• Click the link -> settings , the “open in a new tab” should still be toggled on
• Repeat the above steps with a toggled off state and ensure it also persists correctly

Also added a unit test to check that state.opensInNewWindow is set when props.activeAttributes.target _blank passed in.

Types of changes

Fixes #17770

Checklist:

• [ x ] My code is tested.
• [ x ] My code follows the WordPress code style.
• [ NA ] My code follows the accessibility standards.

[ellatrix]

Looks good, thanks!