vim: Add Separator and RemoveIndent in Join Lines, fix gJ use space join (#22496)

Closes #22492

Release Notes:

- Added Join Lines Separator And RemoveIndent

---------

Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>

crates/editor/src/actions.rs

@@ -204,7 +204,7 @@ impl_actions!(
         ToggleCodeActions,
         ToggleComments,
         UnfoldAt,
-        FoldAtLevel
+        FoldAtLevel,
     ]
 );
 

crates/editor/src/editor.rs

@@ -5851,7 +5851,7 @@ impl Editor {
         });
     }
 
-    pub fn join_lines(&mut self, _: &JoinLines, cx: &mut ViewContext<Self>) {
+    pub fn join_lines_impl(&mut self, insert_whitespace: bool, cx: &mut ViewContext<Self>) {
         if self.read_only(cx) {
             return;
         }
@@ -5893,11 +5893,12 @@ impl Editor {
                     let indent = snapshot.indent_size_for_line(next_line_row);
                     let start_of_next_line = Point::new(next_line_row.0, indent.len);
 
-                    let replace = if snapshot.line_len(next_line_row) > indent.len {
-                        " "
-                    } else {
-                        ""
-                    };
+                    let replace =
+                        if snapshot.line_len(next_line_row) > indent.len && insert_whitespace {
+                            " "
+                        } else {
+                            ""
+                        };
 
                     this.buffer.update(cx, |buffer, cx| {
                         buffer.edit([(end_of_line..start_of_next_line, replace)], None, cx)
@@ -5911,6 +5912,10 @@ impl Editor {
         });
     }
 
+    pub fn join_lines(&mut self, _: &JoinLines, cx: &mut ViewContext<Self>) {
+        self.join_lines_impl(true, cx);
+    }
+
     pub fn sort_lines_case_sensitive(
         &mut self,
         _: &SortLinesCaseSensitive,