Add PostgresRowSequence multi decode

[fabianfett]

No description provided.

[gwynne]

I'll do a PR to rewrite your cute Bash script in Swift later. BTW, a SPM build plugin for codegen would increase your cool factor a lot... 😉 Meanwhile, merge away!

[codecov-commenter]

Codecov Report

Merging #232 (72f2994) into main (262208c) will increase coverage by 3.75%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##             main     #232      +/-   ##
==========================================
+ Coverage   40.15%   43.90%   +3.75%     
==========================================
  Files         115      116       +1     
  Lines        9342     9424      +82     
==========================================
+ Hits         3751     4138     +387     
+ Misses       5591     5286     -305     

Flag	Coverage Δ
unittests	43.90% <0.00%> (+3.75%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...gresNIO/New/PostgresRowSequence-multi-decode.swift	0.00% <0.00%> (ø)
Sources/PostgresNIO/New/PostgresRowSequence.swift	89.73% <ø> (+6.47%)	⬆️
Sources/PostgresNIO/New/PSQLRow-multi-decode.swift	4.44% <0.00%> (+0.19%)	⬆️
Sources/PostgresNIO/Data/PostgresRow.swift	50.00% <0.00%> (+1.02%)	⬆️
...s/PostgresNIO/New/Data/Array+PostgresCodable.swift	94.68% <0.00%> (+1.06%)	⬆️
...rces/PostgresNIO/New/Extensions/Logging+PSQL.swift	19.60% <0.00%> (+1.42%)	⬆️
Sources/PostgresNIO/New/PSQLConnection.swift	30.00% <0.00%> (+2.10%)	⬆️
...ostgresNIO/Deprecated/PostgresMessageDecoder.swift	95.45% <0.00%> (+2.27%)	⬆️
...es/PostgresNIO/New/PSQLBackendMessageDecoder.swift	93.28% <0.00%> (+2.98%)	⬆️
...urces/PostgresNIO/New/Messages/ErrorResponse.swift	32.30% <0.00%> (+3.07%)	⬆️
... and 23 more