problem rendering many asset validation errors

For this dataset: https://dandiarchive.org/dandiset/001169

We are unable to publish due to asset and metadata errors.

When I click the orange buttons to see the validation errors, it takes a long time for this modal window to show up. Sometimes, the button does not work and the page dies.

Here are the error pages:

A few problems here:
1. Why aren't those times valid? Is it because there should be a "T" between the day and the time? That's not clear from the error. It would be nice to understand how to make this a valid datetime.
2. I think this is heavy to load because it is trying to render thousands of asset validation errors. Can we paginate this to avoid that problem?
3. Why is access being reported as an asset-level error? Shouldn't that be a dandiset-level error?
4. Is there a way to add this embargo end date in the UX? I don't think there is.
6. There is no space between the name of the file and the error string. This is not a big deal but it would be nice if we could make this look a bit better.

Open the dataset URL and reproduce the delay or failure from the orange asset-validation buttons, then inspect the validation-error modal and the data it receives. Compare the reported datetime, access, and formatting cases with the issue screenshots; done means the error view remains usable for large result sets and presents the reported validation details clearly.

Written by the indexing model from the issue text.