add code coverage (#852)

Add Cypress code coverage using Istanbul nyc

![image](https://github.com/maputnik/editor/assets/60476837/e7c364b7-7b54-4bf1-85aa-ee6fb19cc40c)

---------

Co-authored-by: shelly_goldblit <shelly_goldblit@dell.com>
Co-authored-by: Harel M <harel.mazor@gmail.com>

vite.config.ts

@@ -1,23 +1,33 @@
-import { defineConfig } from "vite";
+import replace from "@rollup/plugin-replace";
 import react from "@vitejs/plugin-react";
-import replace from '@rollup/plugin-replace';
+import { defineConfig } from "vite";
+import istanbul from "vite-plugin-istanbul";
 
 export default defineConfig({
   server: {
-    port: 8888
+    port: 8888,
+  },
+  build: {
+    sourcemap: true
   },
   plugins: [
     replace({
       preventAssignment: true,
       include: /\/jsonlint-lines-primitives\/lib\/jsonlint.js/,
-      delimiters: ['', ''],
+      delimiters: ["", ""],
       values: {
-          '_token_stack:': ''
-      }
+        "_token_stack:": "",
+      },
     }) as any,
-    react()
+    react(),
+    istanbul({
+      cypress: true,
+      requireEnv: false,
+      nycrcPath: "./.nycrc.json",
+      forceBuildInstrument: true, //Instrument the source code for cypress runs
+    }),
   ],
   define: {
     global: "window",
   },
-});
+});