Added BUILD file for gui2-fw-lib bazel build

This is another step along the way of having Native Bazel builds for Angular
Not fully there yet - waiting for Angular v9 in next 2 weeks
but don't want to wait that long to merge all of this

For most people the main concern is updates to WORKSPACE

Change-Id: I28170b8f8daaa2959327c259fe6a10df075113bb
diff --git a/web/gui2-fw-lib/src/main.prod.ts b/web/gui2-fw-lib/src/main.prod.ts
new file mode 100644
index 0000000..70fd120
--- /dev/null
+++ b/web/gui2-fw-lib/src/main.prod.ts
@@ -0,0 +1,6 @@
+import {enableProdMode} from '@angular/core';
+import {platformBrowser} from '@angular/platform-browser';
+import {AppModuleNgFactory} from './app/app.module.ngfactory';
+
+enableProdMode();
+platformBrowser().bootstrapModuleFactory(AppModuleNgFactory);