Post invalid iso date string success instead of return 400 with error message

New Issue Checklist

• I am not disclosing a vulnerability.
• I am not just asking a question.
• I have searched through existing issues.
• I can reproduce the issue with the latest version of Parse Server.

Issue Description

When post an invalid iso date string, the post success instead of return 400 with error message

Steps to reproduce

curl --location --request POST 'http://localhost:1337/parse/classes/gordonTest' \
--header 'Content-Type: application/json' \
--header 'x-parse-master-key: isotest' \
--data-raw '{
    "isoTest":{
        "__type":"Date",
        "iso":"not iso"
    }
}'

Actual Outcome

The post success and result value is 1970-01-01T00:00:00.000Z

Expected Outcome

Returns 400 with message field isoTest is not a proper iso string

Environment

Server

• Parse Server version: 4.4.0
• Operating system: Mac
• Local or remote host (AWS, Azure, Google Cloud, Heroku, Digital Ocean, etc): local

Database

• System (MongoDB or Postgres): MongoDB
• Database version: 4.2.10
• Local or remote host (MongoDB Atlas, mLab, AWS, Azure, Google Cloud, etc): MongoDB Atlas

Client
http

Logs

[39645] parse-server running on http://localhost:1337/parse
verbose: REQUEST for [POST] /parse/classes/gordonTest: {
  "isoTest": {
    "__type": "Date",
    "iso": "not iso"
  }
} {"method":"POST","url":"/parse/classes/gordonTest","headers":{"content-type":"application/json","x-parse-master-key":"isotest","user-agent":"PostmanRuntime/7.26.8","accept":"*/*","cache-control":"no-cache","postman-token":"6a0c9a67-cfd9-48d6-8c75-8a1cfa6f40b3","host":"localhost:1337","accept-encoding":"gzip, deflate, br","connection":"keep-alive","content-length":"74"},"body":{"isoTest":{"__type":"Date","iso":"not iso"}}}
verbose: RESPONSE from [POST] /parse/classes/gordonTest: {
  "status": 201,
  "response": {
    "objectId": "K01d1kyetL",
    "createdAt": "2020-12-09T21:55:59.158Z"
  },
  "location": "http://localhost:1337/parse/classes/gordonTest/K01d1kyetL"
} {"result":{"status":201,"response":{"objectId":"K01d1kyetL","createdAt":"2020-12-09T21:55:59.158Z"},"location":"http://localhost:1337/parse/classes/gordonTest/K01d1kyetL"}}

Start by reproducing the POST request to /parse/classes/gordonTest with the invalid Date value shown in the issue, then trace how the request validates and stores the iso field. Done means the request returns HTTP 400 with an error identifying isoTest instead of creating an object with a 1970 date.