Fix prepared statements

[fabianfett]

Motivation

Currently Prepared Statements only work if they only use bindings that have the PostgresDataType text. The reason for this is that text has the same representation in text and binary form. For this reason Postgres does not need to know the datatype upfront.

Changes

• Allow users to specify the bindings datatypes explicitly. Fallback to unspecified.
• If binding datatypes are unspecified infer them from the first provided bindings
• Allow users to override the prepared statement name
• Add integration test that validates the behavior

[codecov-commenter]

Codecov Report

Attention: 4 lines in your changes are missing coverage. Please review.

Comparison is base (69ccfdf) 62.28% compared to head (ba9349d) 62.29%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #455      +/-   ##
==========================================
+ Coverage   62.28%   62.29%   +0.01%     
==========================================
  Files         124      125       +1     
  Lines        9937     9946       +9     
==========================================
+ Hits         6189     6196       +7     
- Misses       3748     3750       +2     

Files	Coverage Δ
...nection State Machine/ConnectionStateMachine.swift	63.48% <100.00%> (ø)
...tion State Machine/ExtendedQueryStateMachine.swift	79.59% <100.00%> (ø)
...urces/PostgresNIO/New/PostgresChannelHandler.swift	84.80% <100.00%> (+0.02%)	⬆️
Sources/PostgresNIO/New/PreparedStatement.swift	100.00% <100.00%> (ø)
Sources/PostgresNIO/New/PSQLTask.swift	77.77% <83.33%> (-0.35%)	⬇️
...es/PostgresNIO/Connection/PostgresConnection.swift	42.28% <40.00%> (-0.20%)	⬇️

... and 1 file with indirect coverage changes