Set platform based on server (#32)

* Set platform based on server

Had to refactor a bit to ensure our values get set before VS Code tries
to use them.

* Pave the way for mnemonics on all platforms

* Fix context menus on Mac

* Fix a bunch of things on Mac including menu bar

* Set keybindings based on client's OS

packages/ide/src/fill/dialog.ts

@@ -78,7 +78,7 @@ export class Dialog {
 			this.buttons = this.options.buttons.map((buttonText, buttonIndex) => {
 				const button = document.createElement("button");
 				// TODO: support mnemonics.
-				button.innerText = buttonText.replace("_", "");
+				button.innerText = buttonText.replace("&&", "");
 				button.addEventListener("click", () => {
 					this.actionEmitter.emit({
 						buttonIndex,