Implement a pattern for dealing with upstream APIs which are slow on the first hit; affects [endpoint] (#9233)

* allow serviceData to override cacheSeconds with a longer value

* prevent [endpoint] json cacheSeconds property exceeding service default

* allow ShieldsRuntimeError to specify a cacheSeconds property

By default error responses use the cacheLength of
the service class throwing the error.

This allows error to tell the handling layer the maxAge
that should be set on the error badge response.

* add customExceptions param

This

1. allows us to specify custom properties to pass to the exception
   constructor if we throw any of the standard got errors
   e.g: `ETIMEDOUT`, `ECONNRESET`, etc
2. uses a custom `cacheSeconds` property (if set on the exception)
   to set the response maxAge

* customExceptions --> systemErrors

* errorMessages --> httpErrors

services/jitpack/jitpack-version.service.js

@@ -37,7 +37,7 @@ export default class JitPackVersion extends BaseJsonService {
     return this._requestJson({
       schema,
       url,
-      errorMessages: { 401: 'project not found or private' },
+      httpErrors: { 401: 'project not found or private' },
     })
   }