Do not flicker when switching cmd-hovered words in terminal (#30098)

Closes https://github.com/zed-industries/zed/issues/25110


https://github.com/user-attachments/assets/4624c256-8dfb-48eb-a726-6cf130d946da

Terminal may update its hovered word way before reporting it to the
terminal view, and that processing the file check later.
Hence, store the terminal hover data in the terminal view and avoid
highlights when it's different from what the terminal has (as the source
of truth here).

In addition, now only does hover refreshes when the terminal hover
actually changes, not on every event report.

Release Notes:

- Fixed underline flicker when switching cmd-hovered words in terminal

crates/terminal/src/terminal.rs

@@ -605,7 +605,7 @@ pub struct TerminalContent {
     pub scrolled_to_bottom: bool,
 }
 
-#[derive(Clone)]
+#[derive(Debug, Clone, Eq, PartialEq)]
 pub struct HoveredWord {
     pub word: String,
     pub word_match: RangeInclusive<AlacPoint>,