Update error message on dataset page for large datasets

[rshewitt]

User Story

In order to provide more meaningful responses to our users, datagov wants to update the dataset error message when a dataset is too large to process.

Acceptance Criteria

[ACs should be clearly demoable/verifiable whenever possible. Try specifying them using BDD.]

• GIVEN a large dataset
  WHEN the page loads
  THEN a message indicating the file is too large to render is shown

Background

• when a dataset is too large to process the server can respond with a 500. example

Security Considerations (required)

[Any security concerns that might be implicated in the change. "None" is OK, just be explicit here!]

Sketch

• identify a meaningful and reliable way to determine when a dataset is too large for the UI to handle.
• when that condition is met then a different error message is presented.

[rshewitt]

the provided dataset is fickle and will either render correctly or render a 500 unavailable error. here's a screenshot of the tags/keywords which is most likely the cause of the problem. this isn't all of them.

[hkdctol]

Could be unnecessary after doing #4965