test: add integration test for side effects (#29329)

This new tests keeps track of the known side effects for Angular ES modules.

PR Close #29329

integration/side-effects/snapshots/animations-browser/esm5.js

@@ -0,0 +1,16 @@
+import "tslib";
+
+import "@angular/animations";
+
+import "@angular/core";
+
+function isNode() {
+    return "undefined" !== typeof process;
+}
+
+var _isNode = isNode();
+
+if (_isNode || "undefined" !== typeof Element) if (_isNode || Element.prototype.matches) ; else {
+    var proto = Element.prototype;
+    var fn_1 = proto.matchesSelector || proto.mozMatchesSelector || proto.msMatchesSelector || proto.oMatchesSelector || proto.webkitMatchesSelector;
+}