refs TryGhost/Team#3214
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### <samp>🤖 Generated by Copilot at 92b2412</samp>
This pull request refactors and simplifies the feedback system for the
lexical editor feature. It replaces the nested modal with a new
`FeedbackLexical` component that can be used in different contexts. It
also removes unused code and files related to the old feedback modal.
