tranformWrite follow-ups

[lolopinto]

• createdAt shouldn't be changed in a create -> edit
  

  ent/examples/simple/src/ent/tests/auth_code.test.ts

  Line 68 in c434850

  // expect(authCode2.createdAt).toBe(authCode.createdAt);

• maybe type Data so it matches input? is that a breaking change?
• definitely throw if data is a Map. that's definitely not what we want
• validate that any key returned in data is an inputKey or storageKey of schemaFields and throw if an unexpected key is found
  • it wasn't working for userID in auth code example so checked for both inputKey and storageKey of fieldInfo but that means we could be sending extra and ignoring it now

follow-up to #1765

[lolopinto]

also: documentation for data passed in see #1764