Create schema validation for local Snowplow emitter

What does this MR do and why?

This MR adds local event validator to event_forward controller.

The aim for the validator is to make sure event in development environment are valid.

This solves problem for editor extensions and other services to verify event before sending them to Snowplow collector.

This does not verifies Gitlabs events.

References

Screenshots or screen recordings

Before	After

How to set up and validate locally

// correct payload, should pass

curl 'http://localhost:3000/-/collect_events' \
--data-raw '{
    "schema": "iglu:com.snowplowanalytics.snowplow/payload_data/jsonschema/1-0-4",
    "data": [
      {
        "e": "pv",
        "url": "http://gdk.test:3000/",
        "page": "GitLab",
        "refr": "http://gdk.test:3000/",
        "eid": "4f1939da-210b-4463-92c3-2cdbb6a9c942",
        "tv": "js-3.24.2",
        "tna": "gl",
        "p": "web",
        "cookie": "1",
        "cs": "UTF-8",
        "lang": "en-GB",
        "res": "1728x1117",
        "cd": "30",
        "tz": "Europe/Copenhagen",
        "dtm": "1740062431360",
        "cx": "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",
        "vp": "1728x992",
        "ds": "1713x1038",
        "vid": "2",
        "sid": "4e39265b-81a1-493d-8d62-faa54e35fe48",
        "duid": "654a2c38-edc9-4d34-95bf-c192f7262dd5",
        "stm": "1740135995404"
      }
    ]
  }'

// context has error - incorrect data type assigned for `plan` property (I set it manually to `false`)

curl 'http://localhost:3000/-/collect_events' \
--data-raw '{
"schema": "iglu:com.snowplowanalytics.snowplow/payload_data/jsonschema/1-0-4",
  "data": [
    {
      "e": "pv",
      "url": "http://gdk.test:3000/",
      "page": "GitLab",
      "refr": "http://gdk.test:3000/",
      "eid": "4f1939da-210b-4463-92c3-2cdbb6a9c942",
      "tv": "js-3.24.2",
      "tna": "gl",
      "p": "web",
      "cookie": "1",
      "cs": "UTF-8",
      "lang": "en-GB",
      "res": "1728x1117",
      "cd": "30",
      "tz": "Europe/Copenhagen",
      "dtm": "1740062431360",
      "cx": "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",
      "vp": "1728x992",
      "ds": "1713x1038",
      "vid": "2",
      "sid": "4e39265b-81a1-493d-8d62-faa54e35fe48",
      "duid": "654a2c38-edc9-4d34-95bf-c192f7262dd5",
      "stm": "1740135995404"
    }
  ]
}'

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Related to #561995