Enable Refactor of Source Generation

[milkshakeuk]

• Swap from OdbcConnection to OleDbConnection (makes use of connection pools but is only supported on windows)
• Only target netstandard2.0 for NHapi.SourceGeneration
• Only target net6 for ModelGenerator and NHapi.NUnit.SourceGeneration (net35 is not required to generate source code)
• Safe cross platform generation of directory and file paths
• Abstract IO (File Creation) in NHapi.SourceGeneration with FileAbstraction
• Add unit tests utilising FileAbstraction enables ability to refactor database access and source generation and ensure the results remain unchanged

@AMCN41R I finally did the work to enable refactoring the SourceGen stuff, if you get chance could you have a peak?

[github-actions[bot]]

Unit Test Results

       5 files     111 suites   22s :stopwatch: 1 131 tests 1 054 :heavy_check_mark: 77 :zzz: 0 :x: 2 096 runs  2 014 :heavy_check_mark: 82 :zzz: 0 :x:

Results for commit f8e96ec1.

[github-actions[bot]]

Unit Test Results

       5 files     111 suites   20s :stopwatch: 1 131 tests 1 054 :heavy_check_mark: 77 :zzz: 0 :x: 2 096 runs  2 014 :heavy_check_mark: 82 :zzz: 0 :x:

Results for commit aa79bef0.

[github-actions[bot]]

Unit Test Results

       5 files     111 suites   19s :stopwatch: 1 131 tests 1 054 :heavy_check_mark: 77 :zzz: 0 :x: 2 096 runs  2 014 :heavy_check_mark: 82 :zzz: 0 :x:

Results for commit c0d35a67.