JSON: inconsistent naming

[maria-messerschmidt]

Certain keys in the JSON output are used several times for different value categories:

The name of the file being validated is referred to as:

• "name" inside the non-profile report
• "id" at the top level of the profile report
• "name" in the validationResult object in the profile report

Furthermore, "id" is also used as a key to refer to the message code, e.g. "PKG-2",
and "name" is also used to refer to the profile value "DNA ODF Spreadsheets Preservation Specification“.

These keys should be used consistently to refer to one thing, e.g.

"file_name" or "id" for name of the file
"message_code" for the message code
"profile" for the profile value