WHY
Discovered issue for automatic upgrades of RHOAM in 1.37.0

WHAT
There was an unchecked error in the CSV locator used by the subscription controller. It looks like this error was never thrown and an empty string was being used to determine there was no CSV candidate. Now that we are checking the error it is thrown by the subscription controller on each reconcile https://github.com/integr8ly/integreatly-operator/blob/master/controllers/subscription/csvlocator/csvlocator.go#L113-L116

HOW
Investigate how this csvlocator was supposed to work and fix it.

TESTS
<List of related tests>

DONE
The subscription controller no longer throws errors on each reconcile.