[ML] need a better error message on DFA job wizard if using CCS

[wwang500]

Build: 7.12 GA build

Step to reproduce:

1. Setup a CCS connection to a remote cluster,
2. On the remote cluster, load Kibana sample data log index,
3. On 7.12 cluster, create an index pattern called 7_12:kibana_sample_data_logs,
4. From ml ui, try create a DFA job by using that index pattern,

Observed:
Error: An error occurred fetching analysis fields data. cannot retrieve data because index [7_12:kibana_sample_data_logs] does not exist

Expected:
A better error message that tells CCS function is currently not supported for DFA job.
Ideally this occurs close to the point they select the CCS index pattern.

[elasticmachine]

Pinging @elastic/ml-ui (:ml)