Indices API: Fixed backward compatibility issue

If a 1.4 node needs to forward a GET index API call to a <1.4 master it cannot use the GET index API endpoints as the master has no knowledge of it. This change detects that the master does not understand the initial request and instead tries it again using the old APIs. If these calls also do not work, an error is returned

Closes #8364
I vaguely remember some differences around the indices options used depending on what we retrieve. Are those still 100% bw compatible when downgrading the request? I guess so since if I remember correctly the get index behaviour is already bw compatible but wanted to double check ;)