Implement Create/Rename/Delete workspace edits #4375
Description
New version of LanguageServer.Protocol assembly added CreateFile/RenameFile/DeleteFile operations to the WorkspaceEdit. I took a quick stab at implementing them in 581b13d4fd8fbf734759da735d9433e795844fa0 but things are starting to get a bit too complicated as it's a single SumType array that contains both TextDocumentEdit and Create/Rename/Delete operation, so I'm leaving it to the Razor team to add proper implementation.