Make PostgresRowSequence public

[fabianfett]

Motivation

For the new async interface we need the PostgresRowSequence to be public

Changes

• Make PostgresRowSequence public
• Rename PostgresRowSequence.Iterator to PostgresRowSequence.AsyncIterator (Having an Iterator and an AsyncIterator in the same type is confusing)
• Make PostgresRowSequence decode methods public

Result

Only need to make encoding public

[codecov-commenter]

Codecov Report

Merging #247 (032b377) into main (ba0d2bb) will increase coverage by 4.02%.
The diff coverage is 25.00%.

@@            Coverage Diff             @@
##             main     #247      +/-   ##
==========================================
+ Coverage   39.72%   43.75%   +4.02%     
==========================================
  Files         115      115              
  Lines        9505     9512       +7     
==========================================
+ Hits         3776     4162     +386     
+ Misses       5729     5350     -379     

Flag	Coverage Δ
unittests	43.75% <25.00%> (+4.02%)	⬆️

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% <100.00%> (+6.47%)	⬆️
...ces/PostgresNIO/New/PostgresRow-multi-decode.swift	4.44% <0.00%> (+0.19%)	⬆️
...es/PostgresNIO/Connection/PostgresConnection.swift	15.42% <0.00%> (+0.72%)	⬆️
Sources/PostgresNIO/Data/PostgresRow.swift	50.00% <0.00%> (+1.02%)	⬆️
...s/PostgresNIO/New/Data/Array+PostgresCodable.swift	94.73% <0.00%> (+1.05%)	⬆️
...rces/PostgresNIO/New/Extensions/Logging+PSQL.swift	19.60% <0.00%> (+1.42%)	⬆️
...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 22 more

[gwynne]

This is all adding up to something pretty awesome, isn't it? 👍