Use common dispatcher for public client outbound #2

[vytautas-karpavicius]

What changed?
Same as #4523, but with fixed middleware pointer, which required the revert #4534.

authMiddleware was stored as a pointer, which is not equal to nil which is checked when wrapping a middleware here: https://github.com/yarpc/yarpc-go/blob/dev/api/middleware/outbound.go#L59

Also updated unit test to ensure true nil is used when auth is not configured.

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Stop using DispatcherProvider for creating public client. Instead use common dispatcher from rpc.Factory.

Builder for public client outbound was created which also includes auth middleware initialization. It was previously located within server.go itself. Moving it here allows consolidating all logic related logic in one place and covering it with unit tests.

Why?
To eventually delete DispatcherProvider entirely.

How did you test it?
Existing tests and new unit tests.

Potential risks

Release notes

Documentation Changes

[coveralls]

Pull Request Test Coverage Report for Build b5489b83-bf38-4dff-8e66-962ef2ba48d0

• 28 of 31 (90.32%) changed or added relevant lines in 3 files are covered.
• 25 unchanged lines in 7 files lost coverage.
• Overall coverage increased (+0.05%) to 56.478%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
cmd/server/cadence/server.go	0	3	0.0%

Files with Coverage Reduction	New Missed Lines	%
common/task/weightedRoundRobinTaskScheduler.go	1	89.64%
service/history/execution/mutable_state_task_refresher.go	1	73.82%
common/types/mapper/thrift/shared.go	2	64.52%
service/history/execution/mutable_state_builder.go	2	69.77%
common/task/fifoTaskScheduler.go	4	83.51%
service/history/execution/context.go	6	73.83%
common/persistence/nosql/nosqlExecutionStore.go	9	57.52%

Totals
Change from base Build 0f1ac1c8-56e0-4096-b3bd-1e8bcf2ac3ad:	0.05%
Covered Lines:	80593
Relevant Lines:	142697

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💛 - Coveralls

[mantas-sidlauskas]

move this up

[vytautas-karpavicius]

done