Add exception for blocked sites in search()

[Mr0grog]

Looking at @edsu’s very awesome COVID-19 notebook, it turns out CDX searches can return a special error for blocked sites, e.g. http://web.archive.org/cdx/search/cdx?url=https%3A%2F%2Fnationalpost.com%2Fhealth%2Fbio-warfare-experts-question-why-canada-was-sending-lethal-viruses-to-china&from=20191001000000&showResumeKey=true&resolveRevisits=true

Just like we have a custom BlockedByRobotsError, we should have another error for this, rather than just raising a not-so-great HTTP error.

In this case, the response code is 403 and there is a header like:

X-Archive-Wayback-Runtime-Error: org.archive.util.io.RuntimeIOException: org.archive.wayback.exception.AdministrativeAccessControlException: Blocked Site Error

(And the same text as the header in the response body.)

We can probably follow Wayback’s naming and call this AdministrativeAccessControlException or BlockedSiteError.

It might even make sense to generalize this for any 4xx/5xx response that has an X-Archive-Wayback-Runtime-Error header.

[Mr0grog]

Also worth noting: in the v2 web/timemap/cdx API (that we haven’t yet implemented, see #8) this error is formatted a little differently.

• No response body.

• The header has the same name, but the value is more concise:

  X-Archive-Wayback-Runtime-Error: AdministrativeAccessControlException: Blocked Site Error
  

• Still has a 403 status code.

It’d be good to implement this in a way that supports both.

[Mr0grog]

Some more quick notes:

• It looks like “blocked site error” is not the message for a particular case of AdministrativeAccessControlException; it’s just the friendly message it always shows: https://github.com/internetarchive/wayback/blob/815b6113a33238e3cf7e6a3a5b8ea23708e62760/wayback-core/src/main/java/org/archive/wayback/exception/AdministrativeAccessControlException.java#L26-L34 These two messages are effectively synonymous.

• The Internet Archive’s public Wayback implementation defines a bunch more errors and do does IIPC’s, but it’s not clear whether that’s current with the actual implementation used today or which of those errors are actually used with CDX.

• This refactoring doc on access control appears to imply that AdministrativeAccessControlException and RobotControlAccessControlException (which we already handle) are the only two errors we need to worry about here.

• Digging around GitHub for other Wayback error handling code doesn’t turn up much besides the above two errors.

So, I think we probably don’t need to worry too much about other possible exception types or more generic handling based on the X-Archive-Wayback-Runtime-Error header for now.