Accept API Token in Authorization Header

[winder]

Summary

We have a metrics endpoint to provide prometheus style metrics, it also requires the X-Algo-API-Token: <token> header. Some tools which are able to consume this endpoint, like Telegraf, assume authorization tokens will be provided as bearer tokens, like Authorization: Bearer <token>. So this adds that as a fallback.

Test Plan

Make sure both forms still work:

will@will-algorand:~$ curl http://localhost:10101/v1/status -H "Authorization: Bearer $(cat ~/.algorand/algod.token)"
{"lastRound":253920,"lastConsensusVersion":"https://github.com/algorandfoundation/specs/tree/5615adc36bad610c7f165fa2967f4ecfa75125f0","nextConsensusVersion":"https://github.com/algorandfoundation/specs/tree/5615adc36bad610c7f165fa2967f4ecfa75125f0","nextConsensusVersionRound":253921,"nextConsensusVersionSupported":true,"timeSinceLastRound":2006682505,"catchupTime":0}
will@will-algorand:~$ curl http://localhost:10101/v1/status -H "X-Algo-API-Token: $(cat ~/.algorand/algod.token)"
{"lastRound":253922,"lastConsensusVersion":"https://github.com/algorandfoundation/specs/tree/5615adc36bad610c7f165fa2967f4ecfa75125f0","nextConsensusVersion":"https://github.com/algorandfoundation/specs/tree/5615adc36bad610c7f165fa2967f4ecfa75125f0","nextConsensusVersionRound":253923,"nextConsensusVersionSupported":true,"timeSinceLastRound":3927344369,"catchupTime":0}