[5.6] [fix/UiSettings] ignore certain errors (#13079)

[spalger]

5.6 specific changes:

9facf4d: Since SavedObjectClient in 5.6 has _withKibanaIndexAndMappingFallback, which checks for specific error types and uses a fallback request when they are found. This PR changes the error handling to stop overwriting the es errors and instead decorate them with SavedObjectClient specific details. This means that the error objects no longer have data.type attached to them. Thankfully, it also means that they have the entire elasticsearch response available so we can just check body.error.type instead.

---

• [SavedObjectClient] emit detectable errors

• [uiSettingsService] consume new SavedObjectsClient errors

• [SavedObjectsClient] expose errorTypeHelpers as such

• [elasticsearch/tests] recreate error for each test

• [http] wait for elasticsearch plugin to be ready

• [shortUrl/tests] ensure that create request responds with 200

• [shortUrl] use errorTypeHelpers to filter errors

• [uiSettings/savedObjectsClientStub] stub errorTypeHelpers

• [SavedObjectsClient/errors] expose error module so tests can make errors

• [shortUrl/tests] use actual SavedObjectsClient errors

• [uiSettings/savedObjectsClientStub] use actual errors lib

• [SavedObjectsClient] use decorate instead of "wrap"

• [server/routes/uiSettings] refactor routes to forward Boom errors from uiSettings

• [uiSettings] colocate routes and service

• [testUtils/esTestCluster] use more standard api style

• [testUtils/es] add createCallCluster util

• [testUtils/esTestCluster] add getters for client/callCluster

• [es/healthcheck] ensure that healtcheck stops when server is stopped

• [uiSettings/routes] add param/payload validation

• [uiSettings/routes] add tests that verify error behaviors

[spalger]

jenkins, test this

[spalger]

@tylersmalley @jbudz I talked with one of you while working on it, but this needed to update _withKibanaIndexAndMappingFallback to check for body.error.type rather than data.type since SavedObjectClient is now decorating es errors rather than replacing them

Mind taking a look?

[tylersmalley]

LGTM - also tested with x-pack