chore(events): apply post-merge comments

Introduces a new interface `RequestDetails` to abstract `Request`
providing access to request body and headers.

**BREAKING:** Replace `request: Request` with `request: RequestDetails` at `RequestValidator`.

**BREAKING:** Remove required field `router` at `HttpPostIngressEventPublisher.fromConfig`
  and replace it with `bind(router: Router)`.
  Additionally, the path prefix `/http` will be added inside `HttpPostIngressEventPublisher`.

Relates-to: PR #13931
Signed-off-by: Patrick Jungermann <Patrick.Jungermann@gmail.com>

plugins/events-node/package.json

@@ -24,9 +24,7 @@
     "postpack": "backstage-cli package postpack"
   },
   "dependencies": {
-    "@backstage/backend-plugin-api": "workspace:^",
-    "@types/express": "^4.17.6",
-    "express": "^4.17.1"
+    "@backstage/backend-plugin-api": "workspace:^"
   },
   "devDependencies": {
     "@backstage/cli": "workspace:^"