feat(medusa): Add feature flags to store response (#1819)

**What**
- Add `feature_flags` string array to store response

**Why**
- to provide conditional ui in admin corresponding to enabled features

Co-authored-by: Oliver Windall Juhl <59018053+olivermrbl@users.noreply.github.com>

packages/medusa/src/utils/__tests__/flag-router.ts

@@ -0,0 +1,30 @@
+import { FlagRouter } from "../flag-router"
+
+describe("Flag Router", () => {
+  describe("listFlags", () => {
+    it("should list all feature flags", () => {
+      const flagRouter = new FlagRouter({})
+
+      flagRouter.setFlag("test", false)
+      flagRouter.setFlag("test2", true)
+      flagRouter.setFlag("test3", false)
+
+      const listOfFlags = flagRouter.listFlags()
+
+      expect(listOfFlags).toEqual([
+        {
+          key: "test",
+          value: false,
+        },
+        {
+          key: "test2",
+          value: true,
+        },
+        {
+          key: "test3",
+          value: false,
+        },
+      ])
+    })
+  })
+})

packages/medusa/src/utils/flag-router.ts

@@ -1,4 +1,4 @@
-import { IFlagRouter } from "../types/feature-flags"
+import { FeatureFlagsResponse, IFlagRouter } from "../types/feature-flags"
 
 export class FlagRouter implements IFlagRouter {
   private flags: Record<string, boolean> = {}
@@ -14,4 +14,11 @@ export class FlagRouter implements IFlagRouter {
   public setFlag(key: string, value = true): void {
     this.flags[key] = value
   }
+
+  public listFlags(): FeatureFlagsResponse {
+    return Object.entries(this.flags || {}).map(([key, value]) => ({
+      key,
+      value,
+    }))
+  }
 }