Add public column metadata to Cursor

[lovetodream]

closes #31

[codecov]

Codecov Report

Attention: Patch coverage is 95.17045% with 17 lines in your changes missing coverage. Please review.

Project coverage is 76.95%. Comparing base (94de1ac) to head (a7445a3).

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #34      +/-   ##
==========================================
+ Coverage   76.57%   76.95%   +0.38%     
==========================================
  Files         111      113       +2     
  Lines       13269    13445     +176     
==========================================
+ Hits        10161    10347     +186     
+ Misses       3108     3098      -10     

Files	Coverage Δ
Sources/OracleNIO/Data/Cursor.swift	68.96% <100.00%> (+1.10%)	⬆️
...s/ByteBuffer/ByteBuffer+ReadStringWithFormat.swift	90.00% <100.00%> (ø)
Sources/OracleNIO/Helper/Crypto.swift	100.00% <100.00%> (ø)
...Messages/Coding/OracleFrontendMessageEncoder.swift	79.56% <ø> (-0.10%)	⬇️
...eNIO/Messages/OracleBackendMessage+Parameter.swift	55.23% <100.00%> (-3.74%)	⬇️
Sources/OracleNIO/OracleRow.swift	0.00% <ø> (ø)
Sources/OracleNIO/OracleRowSequence.swift	98.41% <ø> (ø)
Sources/OracleNIO/OracleRowStream.swift	58.06% <ø> (ø)
Sources/OracleNIO/Pool/OracleClient.swift	86.36% <100.00%> (ø)
Sources/OracleNIO/VariadicGenerics.swift	88.29% <ø> (ø)
... and 10 more

... and 2 files with indirect coverage changes