terminal: Make CursorShape configurable (#18530)

This builds on top of @Yevgen's #15840 and combines it with the settings
names introduced in #17572.

Closes #4731.

Release Notes:

- Added a setting for the terminal's default cursor shape. The setting
is `{"terminal": {"cursor_shape": "block"}}``. Possible values: `block`,
`bar`, `hollow`, `underline`.

Demo:


https://github.com/user-attachments/assets/96ed28c2-c222-436b-80cb-7cd63eeb47dd

crates/project/src/terminals.rs

@@ -216,6 +216,7 @@ impl Project {
             shell,
             env,
             Some(settings.blinking),
+            settings.cursor_shape.unwrap_or_default(),
             settings.alternate_scroll,
             settings.max_scroll_history_lines,
             window,