Add C# .NET client

A streaming C# Trino client library with ADO.NET interfaces. Initial contribution
of a mature client from Microsoft.

These are the libraries that make up the client:

Trino.Client - 	Trino .NET SDK

Core client library providing direct access to Trino protocols. Handles session
management, query execution, and result streaming.

Trino.Data.ADO - Trino ADO.NET client

ADO.NET wrapper implementing DbConnection, DbCommand, and IDataReader.
Provides familiar database access patterns and schema discovery functionality.

Trino.Client.Authentication - Authentication providers

Authentication implementations in a separate package to avoid dependency
conflicts.

All are compatible with .NET standard 2.0 which provides compatibility with the
.NET Framework 4.7.2 which is widely used.

Co-Authored-By: Oleg Savin
Co-Authored-By: Ishan Patwa
Co-Authored-By: Dimitry Berger

Author: georgewfisher

.gitignore

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+# Build results
+[Dd]ebug/
+[Dd]ebugPublic/
+[Rr]elease/
+[Rr]eleases/
+x64/
+x86/
+[Ww][Ii][Nn]32/
+[Aa][Rr][Mm]/
+[Aa][Rr][Mm]64/
+bld/
+[Bb]in/
+[Oo]bj/
+[Ll]og/
+[Ll]ogs/
+
+# Visual Studio files
+.vs/
+*.user
+*.userosscache
+*.sln.docstates
+*.userprefs
+
+# ReSharper
+_ReSharper*/
+*.[Rr]e[Ss]harper
+*.DotSettings.user
+
+# NuGet
+*.nupkg
+*.snupkg
+**/packages/*
+!**/packages/build/
+
+# MSTest test Results
+[Tt]est[Rr]esult*/
+[Bb]uild[Ll]og.*
+
+# .NET Core
+project.lock.json
+project.fragment.lock.json
+artifacts/
+
+# Visual Studio Code
+.vscode/*
+!.vscode/settings.json
+!.vscode/tasks.json
+!.vscode/launch.json
+!.vscode/extensions.json
+
+# Visual Studio profiler
+*.psess
+*.vsp
+*.vspx
+*.sap
+
+# Local History
+.localhistory/
+
+# Windows image file caches
+Thumbs.db
+ehthumbs.db
+
+# Folder config file
+Desktop.ini
+
+# Other diff formats
+*.orig