Fix | Fix Unit Tests for GetSqlServerSPN

[arellegue]

This PR is for the addition of Unit Tests of the GetSqlServerSPNs function of SNIProxy class.

The unit tests is to ensure that the GetSqlServerSPNs function returns a port number for TCP protocol and returns an instance name for NP protocol.

In addition, unit tests were added to test the DataTestUtility.ParseDataSource function.

[codecov]

Codecov Report

Attention: Patch coverage is 85.37549% with 37 lines in your changes are missing coverage. Please review.

Project coverage is 72.68%. Comparing base (9056f13) to head (1b6fe95).
Report is 40 commits behind head on main.

❗ Current head 1b6fe95 differs from pull request most recent head b2ef4c5. Consider uploading reports for the commit b2ef4c5 to get more accurate results

Files	Patch %	Lines
...qlClient/src/Microsoft/Data/SqlClient/TdsParser.cs	81.37%	19 Missing ⚠️
...crosoft/Data/SqlClient/SSPI/SSPIContextProvider.cs	64.70%	6 Missing ⚠️
...t/Data/SqlClient/SSPI/NativeSSPIContextProvider.cs	85.71%	3 Missing ⚠️
...icrosoft/Data/SqlClient/Server/MetadataUtilsSmi.cs	85.71%	3 Missing ⚠️
...icrosoft/Data/SqlClient/SqlSequentialTextReader.cs	81.25%	3 Missing ⚠️
.../netcore/src/Microsoft/Data/SqlClient/TdsParser.cs	87.50%	1 Missing ⚠️
...osoft/Data/SqlClient/TdsParserStateObjectNative.cs	66.66%	1 Missing ⚠️
...nt/netfx/src/Microsoft/Data/SqlClient/TdsParser.cs	85.71%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2442      +/-   ##
==========================================
+ Coverage   66.85%   72.68%   +5.82%     
==========================================
  Files         304      313       +9     
  Lines       61576    61727     +151     
==========================================
+ Hits        41168    44865    +3697     
+ Misses      20408    16862    -3546     

Flag	Coverage Δ
addons	92.88% <ø> (∅)
netcore	76.95% <91.11%> (+5.88%)	⬆️
netfx	70.40% <83.33%> (+5.80%)	⬆️

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