Improve JSON parse error handling

[kd-ods]

Describe the bug

At the moment, when the JSON is invalid, the paste-box is emptied and replaced with the text 'undefined'.

This is not user-friendly: users don't know what's caused the problem and they aren't assisted to recover from it.

To Reproduce

Steps to reproduce the behaviour:

1. Paste the following into the visualiser and click draw

[
  {
    "statementId": "1dc0e987-5c57-4a1c-b3ad-61353b66a9b7",
    "declarationSubject": "c359f58d2977",
    "statementDate": "2020-03-04",
    "publicationDetails": {
      "bodsVersion": "0.4"
    },
    "recordId": "c359f58d2977",
    "recordStatus": "new",
    "recordType": "entity",
    "recordDetails": {
      "name": "Profitech Ltd",
      "foundingDate": "2019-09-03"
    }
  },
  {
    "statementId": "019a93f1-e470-42e9-957b-03559861b2e2",
    "declarationSubject": "c359f58d2977",
    "statementDate": "2020-03-04",
    "publicationDetails": {
      "bodsVersion": "0.4"
    },
    "recordId": "10478c6cf6de",
    "recordStatus": "new",
    "recordType": "person",
    "recordDetails": {
      "personType": "knownPerson",
      "names": [
        {
          "type": "legal",
          "fullName": "Jennifer Hewitson-Smith",
          "givenName": "Jennifer",
          "familyName": "Hewitson-Smith"
        }
      ]
    }
  },
  {
    "statementId": "fbfd0547-d0c6-4a00-b559-5c5e91c34f5c",
    "declarationSubject": "c359f58d2977",
    "statementDate": "2020-03-04",
    "publicationDetails": {
      "bodsVersion": "0.4"
    },
    "recordId": "93b53022ae6a",
    "recordStatus": "new",
    "recordType": "relationship",
    "recordDetails": {
      "subject": "c359f58d2977",
      "interestedParty": "10478c6cf6de"
      "interests": [
        {}
      ]
    }
  }
]

(There is a missing comma at the end of '"interestedParty": "10478c6cf6de"', 7 lines from the bottom.)

Expected behaviour

Ideally:

• On clicking 'Draw', an alert box would appear, saying 'The JSON is not valid. [...]' and then simply pass on the error message. (So in the above case: 'The JSON is not valid. SyntaxError: JSON.parse: expected ',' or '}' after property value in object at line 52 column 7 of the JSON data')
• The JSON data would remain in the paste-box, so that once the error message is dismissed, the data can be corrected.