`ims` Service `getAccessToken` Should hide exceptions

[bstopp]

Expected Behaviour

When an exception occurs in the fetching of a new Access token, the IMS Service should capture any possible Feign runtime exceptions and either:

a) log it, returning nothing.
b) Transform it the exception into a meaningful, recoverable or non-recoverable state.

Actual Behaviour

All of the Feign runtime exceptions bubble up to the caller.