Introducing a structured logger, zap, to the internal logger. This is to address a common user complaint where logs are just a wall of text which is hard to parse through and find the error that's causing application to fail.

In this diff we implement current public API `Logger` via Zap, and adding private (for now) `withLogger` and `exitCode` which will be public once we iterate on the new logging interface. 

Following is a list of all new messages and fields.

msg | field | field
-- | -- | --
providing | type | constructor
supplying | type |  
invoke | function |  
received signal | signal |  
startup failed, rolling back | error |  
could not rollback cleanly | error |  
error encountered while applying options | error |  
fx.Invoke failed | function |  error |
failed to start | error |  
failed to stop cleanly | error |  
running |   |  



Ref T5424311 GO-77