feat(csharp): implement protocol selection for REST API support

.rat-excludes

@@ -15,3 +15,4 @@
 .github/pull_request_template.md
 .gitmodules
 *.csproj
+*.sln

csharp/Apache.Arrow.Adbc.Drivers.Databricks.sln

@@ -1,20 +1,3 @@
-  /*
-  * Copyright (c) 2025 ADBC Drivers Contributors
-  *
-  * Licensed under the Apache License, Version 2.0 (the "License");
-  * you may not use this file except in compliance with the License.
-  * You may obtain a copy of the License at
-  *
-  *    http://www.apache.org/licenses/LICENSE-2.0
-  *
-  * Unless required by applicable law or agreed to in writing, software
-  * distributed under the License is distributed on an "AS IS" BASIS,
-  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
-  implied.
-  * See the License for the specific language governing permissions and
-  * limitations under the License.
-  */
-
 Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio Version 17
 VisualStudioVersion = 17.14.36623.8 d17.14