Merge #8054

8054: Item movers r=matklad a=ivan770

Closes #6823

https://user-images.githubusercontent.com/14003886/111331579-b4f43480-8679-11eb-9af0-e4dabacc4923.mp4

Implementation issues:
- [ ] Most of items are non-movable, since _movability_ of any item has to be determined manually. Common ones are movable though
- [x] Cursor should move with the item

Co-authored-by: ivan770 <leshenko.ivan770@gmail.com>

crates/rust-analyzer/src/to_proto.rs

@@ -658,6 +658,18 @@ pub(crate) fn goto_definition_response(
     }
 }
 
+pub(crate) fn text_document_edit(
+    snap: &GlobalStateSnapshot,
+    file_id: FileId,
+    edit: TextEdit,
+) -> Result<lsp_types::TextDocumentEdit> {
+    let text_document = optional_versioned_text_document_identifier(snap, file_id);
+    let line_index = snap.file_line_index(file_id)?;
+    let edits =
+        edit.into_iter().map(|it| lsp_types::OneOf::Left(text_edit(&line_index, it))).collect();
+    Ok(lsp_types::TextDocumentEdit { text_document, edits })
+}
+
 pub(crate) fn snippet_text_document_edit(
     snap: &GlobalStateSnapshot,
     is_snippet: bool,