Initialise flipper-ui-browser with socket connection

Summary:
This diff sets up the socket connection between flipper-browser and flipper-server, and verifies that the initial UI initialisation work (e.g. `get-config` command works). The initial RenderHost is initialised as well based on the config and browser APIs.

Note that flipper-ui-core itself isn't started yet, as that has still a plethora of node imports, so Metro will correctly refuse to bundle

Not in this diff
* remove Node usage from flipper-ui-core
* implement all RenderHost APIs

Reviewed By: aigoncharov

Differential Revision: D32644074

fbshipit-source-id: 2c8065caf0191771a3867b69a431ca50eeb7a5a3

desktop/static/index.web.dev.html

@@ -10,6 +10,7 @@
       window.flipperConfig = {
         theme: 'light',
         entryPoint: 'flipper-ui-browser/src/index-fast-refresh.bundle?platform=web&dev=true&minify=false',
+        debug: true,
       }
     </script>
     <style>
@@ -62,7 +63,12 @@
       (function() {
         // FIXME: needed to make Metro work
         window.global = window;
-        global.electronRequire = window.require;
+        // global.electronRequire = function(path) {
+        //   // debugger;
+        //   // throw(new Error("Tried to require: " + path));
+        //   console.error("Tried to require " + path);
+        //   return {};
+        // };
 
         let suppressErrors = false;
 
@@ -87,6 +93,10 @@
           box.textContent = text;
         }
         window.flipperShowError = openError;
+        window.flipperHideError = () => {
+          const box = document.querySelector('.__infinity-dev-box-error');
+          box.setAttribute('hidden', true);
+        }
 
         // load correct theme (n.b. this doesn't handle system value specifically, will assume light in such cases)
         try {