Provide easy means for introspecting upload validation failures

[yarikoptic]

ATM people would need to either

• look at the log which is very verbose to understand what exactly failed to validate and how
• dandi validate could be used then to provide a better view

I think that we could make it more helpful if we separate rendering of validation (in logs, on screen) from storing its results and

• serialize validator results and store them in some .json file e.g. along with the .log file for upload
• provide visualizers

now validate and upload they both do validation, and then provide alternative means to render results and behavior. If we separate out execution, from rendering with intermediate dump of all records, we could make it easier to re-render in various grouppings/filtering (#1743 ) etc.

Related issues/PRs

• Replace bidsschematools with bids-validator-deno invocation/processing #1597