Error handling for MURs that are missing documents

[JonellaCulmer]

What we're after:
To catch missing MUR documents in the future, we need to incorporate better error handling and alerting when an error occurs.

For more details:
This is related to fecgov/openFEC#4361
and fecgov/openFEC#4364

Question:

• Do all MURs have documents

Completion criteria:

• Front-end should show a warning message on a MUR when there are missing documents, but the page should still load.

[patphongs]

@JonellaCulmer @dorothyyeager I need some help as to what we should show when there are no MUR documents due to a failed document loading issue in the API. This is what I have so far, could you please help to refine it?

[JonellaCulmer]

@patphongs We have draft language below which is not much different from what you have there.

We're wondering though, what kind of error has occurred? We want to be specific - server error? Internal error? Yada yada. Also, are these just for new MURs or can this happen to older MURs and the documents "disappear" and need to be fixed?

What we have so far:
Sorry, there was a problem loading these documents. Please try again later.

cc: @dorothyyeager

[patphongs]

@JonellaCulmer @dorothyyeager Typically MUR document problems tend to happen when the documents failed to load when re-indexed in ElasticSearch. We noticed last time this happened that it did not effect every MUR, but probably half. So I think the error message that you have works perfectly, since it talks about a problem with loading documents. I'll update the PR.