Setup js unit test and code coverage framework

(1) Use frontend-maven-plugin to integrate frontend development
(2) Use jest as test tool
(3) Use webpack to create webapp bundle
(4) Coverage data is saved in target/jscoverage

Issue-ID: POLICY-2311
Signed-off-by: huaxing <huaxing.jin@est.tech>
Change-Id: I34fb7487c1e0ca29114eb7accba8bb7c4812da34
diff --git a/.gitignore b/.gitignore
index 8ae43ea..f4225bc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,4 +8,6 @@
 target
 .metadata/
 /bin/
-.idea
+# IntelliJ files
+.idea/
+**/*.iml