Add keyboard controls to link editing/adding links

[markhowellsmead]

What problem does this address?

As surfaced in #60444, many experienced users will be familiar with the option to use keyboard commands like Ctrl + K to add links to a selected item.

What is your proposed solution?

Consider adding common keyboard controls to the Block Editor to expedite the workflow for users who write and create a lot of content, adopting common keyboard usage patterns from other apps like Word.