New postgres protocol implementation

[coveralls]

Pull Request Test Coverage Report for Build 748758318

• 237 of 626 (37.86%) changed or added relevant lines in 7 files are covered.
• 160 unchanged lines in 8 files lost coverage.
• Overall coverage decreased (-5.8%) to 62.624%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
sql_engine/scalar/src/lib.rs	2	4	50.0%
postgres/query_response/src/lib.rs	96	100	96.0%
sql_engine/entities/types/src/lib.rs	9	13	69.23%
postgres/wire_protocol/src/lib.rs	0	104	0.0%
node_engine/src/lib.rs	0	118	0.0%
node_engine/src/query_engine/mod.rs	127	284	44.72%
<!--	Total:	237	626	37.86%	-->

Files with Coverage Reduction	New Missed Lines	%
node_engine/src/lib.rs	1	0%
node_engine/src/session/mod.rs	2	84.62%
sql_engine/query_processing/type_inference/src/lib.rs	3	64.0%
sql_engine/scalar/src/lib.rs	3	52.46%
sql_engine/data_manipulation/query_result/src/lib.rs	4	51.35%
sql_engine/data_manipulation/query_plan/src/lib.rs	8	85.05%
postgres/query_response/src/lib.rs	65	54.55%
node_engine/src/query_engine/mod.rs	74	49.79%
<!--	Total:	160		-->

Totals
Change from base Build 738862597:	-5.8%
Covered Lines:	2520
Relevant Lines:	4024

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💛 - Coveralls