[CL-573] Move all svg icons to new libs/assets (#16020)

* create libs/assets

* treeshake lib and filter out non-icons from icon story

* update docs

* fix icon colors in browser and desktop

* better name for vault icon

* move illustrations

libs/assets/src/svg/icon-service.ts

@@ -0,0 +1,25 @@
+class Icon {
+  constructor(readonly svg: string) {}
+}
+
+// We only export the type to prohibit the creation of Icons without using
+// the `svgIcon` template literal tag.
+export type { Icon };
+
+export function isIcon(icon: unknown): icon is Icon {
+  return icon instanceof Icon;
+}
+
+export class DynamicContentNotAllowedError extends Error {
+  constructor() {
+    super("Dynamic content in icons is not allowed due to risk of user-injected XSS.");
+  }
+}
+
+export function svgIcon(strings: TemplateStringsArray, ...values: unknown[]): Icon {
+  if (values.length > 0) {
+    throw new DynamicContentNotAllowedError();
+  }
+
+  return new Icon(strings[0]);
+}