Added 2-way proto-thrift mapper

[vytautas-karpavicius]

What changed? Up to this point, there was one way mapping for thrift to proto types. This was used to create a compatibility layer, such that existing client could communicate in gRPC with server.

Now adding mapping in other direction as well. This will be used to convert internal of client itself to use proto types, but still accept publicly exposed thrift types.

Why? To migrate internals of go client to use proto types.

Only publicly exposed API surface will keep thrift for compatibility.

How did you test it? Added unit tests that ensures the following invariant hold true:

assert.Equal(t, item, proto.TYPE_NAME(thrift.TYPE_NAME(item)))

Potential risks New mappers not used yet.

[coveralls]

Pull Request Test Coverage Report for Build dde8d9ef-8a19-406a-9811-46bbaacfd9b5

• 1289 of 5010 (25.73%) changed or added relevant lines in 17 files are covered.
• 23 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-8.4%) to 63.128%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
internal/compatibility/thrift/helpers.go	0	15	0.0%
internal/compatibility/proto/helpers.go	17	36	47.22%
internal/compatibility/proto/decision.go	125	158	79.11%
internal/compatibility/proto/error.go	0	50	0.0%
internal/compatibility/thrift/response.go	134	258	51.94%
internal/compatibility/thrift/decision.go	0	148	0.0%
internal/compatibility/adapter.go	33	238	13.87%
internal/compatibility/thrift/enum.go	56	283	19.79%
internal/compatibility/proto/enum.go	56	295	18.98%
internal/compatibility/proto/response.go	0	260	0.0%
<!--	Total:	1289	5010	25.73%	-->

Files with Coverage Reduction	New Missed Lines	%
internal/internal_task_pollers.go	2	80.45%
internal/compatibility/adapter.go	21	21.0%
<!--	Total:	23		-->

Totals
Change from base Build 824b8973-99ad-4f10-9ea7-7b04277109c0:	-8.4%
Covered Lines:	12168
Relevant Lines:	19275

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💛 - Coveralls