Set proper service context in client tchannels

[isopropylcyanide]

Summary

PR Status	Type	Impact level
Ready	Bug	High

Description

• Set tchannel service name to be the same as server (gateway) name
• Add another helpful log to be tracked in ELK when the channel is created successfully

Motivation

• The newly initiated channels as part of Dedicated TChannel Client Per Callee Service #778 were passed a service name of their client-id while in essence they should use the same service name as the gateway. This is because even though there are dedicated channels now, they still need to talk to the routing sidecar as one unit

• When we landed Dedicated TChannel Client Per Callee Service #778 some backends that had ACL enabled had their requests outright rejected by the sidecar router.
  

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How was this tested?

• Tested in local that the new client channels are now passed the same value as of the server

Benchmarks

• N/A

[coveralls]

Coverage increased (+0.002%) to 69.582% when pulling d1cc9ad on fix-tchannel-caller-id into a8c5d9c on master.