editor: Represent scroll offset with more precision (#39367)

Closes #5355

Release Notes:

- Fixed rendering glitches with files with more than 16 million lines
(that occured due to floating number rounding errors).

---------

Co-authored-by: Smit Barmase <heysmitbarmase@gmail.com>

crates/editor/src/display_map/block_map.rs

@@ -1395,7 +1395,7 @@ impl BlockSnapshot {
         })
     }
 
-    pub fn sticky_header_excerpt(&self, position: f32) -> Option<StickyHeaderExcerpt<'_>> {
+    pub(crate) fn sticky_header_excerpt(&self, position: f64) -> Option<StickyHeaderExcerpt<'_>> {
         let top_row = position as u32;
         let mut cursor = self.transforms.cursor::<BlockRow>(());
         cursor.seek(&BlockRow(top_row), Bias::Right);