lsp: add $/progress report (#13294)

Heavily inspired by https://github.com/nvim-lua/lsp-status.nvim.
listen to the LspProgressUpdate event to update your statusline.

runtime/lua/vim/lsp/protocol.lua

@@ -728,6 +728,9 @@ function protocol.make_client_capabilities()
       dynamicRegistration = false;
     };
     experimental = nil;
+    window = {
+      workDoneProgress = true;
+    }
   }
 end