Vega add filter integration errors with non-default index pattern

[flash1293]

Kibana version: master

Elasticsearch version:

Server OS version:

Browser version:

Browser OS version:

Original install method (e.g. download page, yum, from source, etc.):

Describe the bug: Using the kibanaAddFilter vega integration to set filters from within vega does not work correctly when the filter is applied to a field which isn't present in the default index pattern. This happens because the filter manager is looking up the field by name in the default index pattern and doesn't check for the case it is not available.

Steps to reproduce:

1. Pick ecommerce sample index pattern as default one
2. Ingest some logstash data
3. Create this vega visualization: https://gist.github.com/nyurik/3c579fb8e81c8a981d4b267ad1767227
4. Click one of the extension labels on the left

Expected behavior:
Should not crash the filter bar

Screenshots (if relevant):

Errors in browser console (if relevant):

Provide logs and/or server output (if relevant):

Any additional context:

[elasticmachine]

Pinging @elastic/kibana-app (Team:KibanaApp)

[elasticmachine]

Pinging @elastic/kibana-app-arch (Team:AppArch)