Index information is not updated on UI when some of the index nodes are not responsive

Steps to repro:

a. Setup a cluster with 2 KV+Query and 3 indexer nodes

b. Load sample buckets and create indexes

c. Stop one of the indexer service

d. Create a new index

The newly created index is not seen on the UI. The issue can also be seen with the following steps:

a. Setup a cluster with 2 KV+Query and 3 indexer nodes

b. Load sample buckets and create indexes

c. Stop all the 3 indexer nodes

d. Bring back 2 of the indexer nodes

e. The UI does not show any indexes

The reason behind such an inconsistency is because, the "getIndexStatus" request will collect index information from all the nodes and if there is a failed node in the quorum, it will return the HTTP response as "500-Internal server error" along with the list of indexes from active nodes. Also the "code" field in response JSON set to "error". Because of this, the UI is not updating the information although response contains indexes from active indexer nodes.

Ideally, the expectation is that UI shows the indexes that are currently available and also show a warning like "the index information shown is not complete as some index nodes are not responsive"