Rework go to line infrastructure (#23654)

Closes https://github.com/zed-industries/zed/issues/12024


https://github.com/user-attachments/assets/60ea3dbd-b594-4bf5-a44d-4bff925b815f

* Fixes incorrect line selection for certain corner cases

Before:

<img width="1728" alt="image"
src="https://github.com/user-attachments/assets/35aaee6c-c120-4bf1-9355-448a29d1b9b5"
/>

After:

<img width="1728" alt="image"
src="https://github.com/user-attachments/assets/abd97339-4594-4e8e-8605-50d74581ae86"
/>


* Reworks https://github.com/zed-industries/zed/pull/16420 to display
selection length with less performance overhead.
Improves the performance more, doing a single selections loop instead of
two.

* Fixes incorrect caret position display when text contains UTF-8 chars
with size > 1
Also fixes tooltop values for this case

* Fixes go to line to treat UTF-8 chars with size > 1 properly when
navigating

* Adds a way to fill go to line text editor with its tooltip on `Tab`

Release Notes:

- Fixed incorrect UTF-8 characters handling in `GoToLine` and caret
position

crates/text/src/tests.rs

@@ -261,10 +261,25 @@ fn test_text_summary_for_range() {
         BufferId::new(1).unwrap(),
         "ab\nefg\nhklm\nnopqrs\ntuvwxyz".into(),
     );
+    assert_eq!(
+        buffer.text_summary_for_range::<TextSummary, _>(0..2),
+        TextSummary {
+            len: 2,
+            chars: 2,
+            len_utf16: OffsetUtf16(2),
+            lines: Point::new(0, 2),
+            first_line_chars: 2,
+            last_line_chars: 2,
+            last_line_len_utf16: 2,
+            longest_row: 0,
+            longest_row_chars: 2,
+        }
+    );
     assert_eq!(
         buffer.text_summary_for_range::<TextSummary, _>(1..3),
         TextSummary {
             len: 2,
+            chars: 2,
             len_utf16: OffsetUtf16(2),
             lines: Point::new(1, 0),
             first_line_chars: 1,
@@ -278,6 +293,7 @@ fn test_text_summary_for_range() {
         buffer.text_summary_for_range::<TextSummary, _>(1..12),
         TextSummary {
             len: 11,
+            chars: 11,
             len_utf16: OffsetUtf16(11),
             lines: Point::new(3, 0),
             first_line_chars: 1,
@@ -291,6 +307,7 @@ fn test_text_summary_for_range() {
         buffer.text_summary_for_range::<TextSummary, _>(0..20),
         TextSummary {
             len: 20,
+            chars: 20,
             len_utf16: OffsetUtf16(20),
             lines: Point::new(4, 1),
             first_line_chars: 2,
@@ -304,6 +321,7 @@ fn test_text_summary_for_range() {
         buffer.text_summary_for_range::<TextSummary, _>(0..22),
         TextSummary {
             len: 22,
+            chars: 22,
             len_utf16: OffsetUtf16(22),
             lines: Point::new(4, 3),
             first_line_chars: 2,
@@ -317,6 +335,7 @@ fn test_text_summary_for_range() {
         buffer.text_summary_for_range::<TextSummary, _>(7..22),
         TextSummary {
             len: 15,
+            chars: 15,
             len_utf16: OffsetUtf16(15),
             lines: Point::new(2, 3),
             first_line_chars: 4,