Support binary data transfer in COPY FROM

[ahoppen]

My benchmark of transferring the integers from 0 to 1,000,000 both as an integer and as a string was about the same speed as the old text-based transfer. I believe that the binary transfer will start to show significant benefits when transferring binary data, other fields that don't need to be represented as fields and also means that the user doesn't need to worry about escapping their data.

A call to binary transfer data looks as follows

let records: [(id: Int, name: String)] = [(1, "Alice"), (42, "Bob")]
try await conn.copyFromBinary(table: "copy_table", columns: ["id", "name"], logger: .psqlTest) { writer in
    for record in records {
        try await writer.writeRow { columnWriter in
            try columnWriter.writeColumn(Int32(record.id))
            try columnWriter.writeColumn(record.name)
        }
    }
}

[codecov]

Codecov Report

❌ Patch coverage is 95.31250% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 75.73%. Comparing base (4db2fde) to head (42f110e).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...esNIO/Connection/PostgresConnection+CopyFrom.swift	95.31%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #573      +/-   ##
==========================================
+ Coverage   75.42%   75.73%   +0.30%     
==========================================
  Files         134      134              
  Lines        9887     9976      +89     
==========================================
+ Hits         7457     7555      +98     
+ Misses       2430     2421       -9     

Files with missing lines	Coverage Δ
...esNIO/Connection/PostgresConnection+CopyFrom.swift	93.88% <95.31%> (+0.78%)	⬆️

... and 6 files with indirect coverage changes

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