Combine duplicate implementations of toInstrumentedOdspTokenFetcher

[markfields]

One is toInstrumentedOdspTokenFetcher in odspUtils.ts (used by document service factory), and the other is toInstrumentedTokenFetcher in odspDriverUrlResolverForShareLink.ts (used by url resolver).

I don't think we would need two implementations. And it tripped me up, because I was expecting the behavior of one when looking at the logs, but it was going through the other which doesn't behave the same way.

[markfields]

In particular, the url resolver one doesn't wrap thrown errors with fetchTokenError errorType, so it is basically impossible to aggregate them together in telemetry, which is a big miss.