[Feature]: Escape in the browser address bar should back out one step at a time, like Chrome

Problem or use case

In Orca's in-app browser, Escape in the address bar only closes the suggestion list. If you edited the address, the edited text stays and the cursor stays in the bar, so there is no keyboard way to undo the edit or get back to the page. Chrome's address bar lets you back out one step per Escape.

Proposed solution

Match Chrome's address bar. Each Escape does the first step that applies:

1. If a suggestion was selected with the arrow keys, go back to the typed text and keep the list open.
2. If the suggestion list is open, close it.
3. If the text differs from the page address, revert to the page address with all of it selected.
4. Otherwise, move focus to the page.

An Escape pressed while an IME is composing, for example Korean, closes the list and keeps the composed text, as Chrome does.

Alternatives or additional context

The behavior comes from Chromium's OmniboxEditModel::OnEscapeKeyPressed. The same order should apply to local pages, client-hosted pages, remote streamed pages, and the document preview's address edit.