Add filter_format field for Column in pickers

Add the option to provide a formatting function for the filtering of
picker columns that is separate from the formatting function for
displaying it in the view.
Use this new option for the "path" column of the workspace diagnostics
picker, so that we are filtering on the full (relative) file path,
instead of the truncated value.

Fixes #13608

helix-term/src/commands/lsp.rs

@@ -281,6 +281,16 @@ fn diag_picker(
                 } else {
                     Default::default()
                 }
+            })
+            .with_filter_format(|item: &PickerDiagnostic, _| {
+                if let Some(path) = item.location.uri.as_path() {
+                    path::get_relative_path(path)
+                        .to_string_lossy()
+                        .to_string()
+                        .into()
+                } else {
+                    Default::default()
+                }
             }),
         );
         primary_column += 1;

helix-term/src/ui/picker.rs

@@ -137,7 +137,7 @@ fn inject_nucleo_item<T, D>(
 ) {
     injector.push(item, |item, dst| {
         for (column, text) in columns.iter().filter(|column| column.filter).zip(dst) {
-            *text = column.format_text(item, editor_data).into()
+            *text = column.format_filter_text(item, editor_data).into()
         }
     });
 }
@@ -189,6 +189,7 @@ type ColumnFormatFn<T, D> = for<'a> fn(&'a T, &'a D) -> Cell<'a>;
 pub struct Column<T, D> {
     name: Arc<str>,
     format: ColumnFormatFn<T, D>,
+    filter_format: ColumnFormatFn<T, D>,
     /// Whether the column should be passed to nucleo for matching and filtering.
     /// `DynamicPicker` uses this so that the dynamic column (for example regex in
     /// global search) is not used for filtering twice.
@@ -201,6 +202,7 @@ impl<T, D> Column<T, D> {
         Self {
             name: name.into(),
             format,
+            filter_format: format,
             filter: true,
             hidden: false,
         }
@@ -213,6 +215,7 @@ impl<T, D> Column<T, D> {
         Self {
             name: name.into(),
             format,
+            filter_format: format,
             filter: false,
             hidden: true,
         }
@@ -223,12 +226,18 @@ impl<T, D> Column<T, D> {
         self
     }
 
+    pub fn with_filter_format(mut self, format_fn: ColumnFormatFn<T, D>) -> Self {
+        self.filter_format = format_fn;
+        self
+    }
+
     fn format<'a>(&self, item: &'a T, data: &'a D) -> Cell<'a> {
         (self.format)(item, data)
     }
 
-    fn format_text<'a>(&self, item: &'a T, data: &'a D) -> Cow<'a, str> {
+    fn format_filter_text<'a>(&self, item: &'a T, data: &'a D) -> Cow<'a, str> {
-        let text: String = self.format(item, data).content.into();
+        let cell = (self.filter_format)(item, data);
+        let text: String = cell.content.into();
         text.into()
     }
 }