[workspace]: file.rename command should resolve with the file stat after the successful execution

[kittaakos]

When executing the file.rename command, the caller does not know if the command has been executed or not. Maybe the user has canceled the operation. Clients could use the command if the new file state is returned from the handler after the rename. Currently, it's not possible to reuse the command:

theia/packages/workspace/src/browser/workspace-commands.ts

Line 302 in f925bdb

this.fileService.move(oldUri, newUri);

Feature Description:

Please return the file stat from the command handler when the operation is OK. Otherwise, undefined.

Pipe-dream: expose the rename operation like other workspace command handlers (delete, duplicate) to help Theia extensibility.