build: create sass_bundle bazel rule (#10055)

This defines a bazel rule to bundle sass partials into a single file
using the "scss-bundle" npm package. The rule definition is commented so
that it can serve as an example for creating other rules in the future.

I've also added the missing build file for badge so that its theme can
be included in the bundle.

Author: jelbourn

WORKSPACE

@@ -1,4 +1,4 @@
-workspace(name = "angular_material_src")
+workspace(name = "angular_material")
 
 # Add nodejs rules
 git_repository(

components.bzl

@@ -0,0 +1,37 @@
+# List of all @angular/material components / subpackages.
+MATERIAL_PACKAGES = [
+  "autocomplete",
+  "badge",
+  "bottom-sheet",
+  "button-toggle",
+  "button",
+  "card",
+  "checkbox",
+  "chips",
+  "core",
+  "datepicker",
+  "dialog",
+  "divider",
+  "expansion",
+  "form-field",
+  "grid-list",
+  "icon",
+  "input",
+  "list",
+  "menu",
+  "paginator",
+  "progress-bar",
+  "progress-spinner",
+  "radio",
+  "select",
+  "sidenav",
+  "slide-toggle",
+  "slider",
+  "snack-bar",
+  "sort",
+  "stepper",
+  "table",
+  "tabs",
+  "toolbar",
+  "tooltip",
+]