Adding ability to add custom wire protocol commands in .NET bindings.

This commit allows projects that use a WebDriver-like JSON-over-HTTP wire
protocol to add additional end points for their use. It does this by
exposing (and renaming) a formally internal method on the singleton
CommandInfoRepository class. To add additonal commands, one would call the
TryAddCommand method, which is now public. Fixes issue #8594.

Author: jimevans

Diff for: dotnet/src/webdriver/PhantomJS/PhantomJSDriver.cs

@@ -151,7 +151,7 @@ public PhantomJSDriver(PhantomJSDriverService service, PhantomJSOptions options,
         {
             // Add the custom commandInfo of PhantomJSDriver
             CommandInfo commandInfo = new CommandInfo(CommandInfo.PostCommand, "/session/{sessionId}/phantom/execute");
-            CommandInfoRepository.Instance.TryAddAdditionalCommand(CommandExecutePhantomScript, commandInfo);
+            CommandInfoRepository.Instance.TryAddCommand(CommandExecutePhantomScript, commandInfo);
         }
 
         /// <summary>

Diff for: dotnet/src/webdriver/Remote/CommandInfoRepository.cs

@@ -94,16 +94,17 @@ public CommandInfo GetCommandInfo(string commandName)
         }
 
         /// <summary>
-        /// Tries the add an additional command to the list of known commands.
+        /// Tries to add a command to the list of known commands.
         /// </summary>
         /// <param name="commandName">Name of the command.</param>
         /// <param name="commandInfo">The command information.</param>
         /// <returns><see langword="true"/> if the new command has been added successfully; otherwise, <see langword="false"/>.</returns>
         /// <remarks>
         /// This method is used by WebDriver implementations to add additional custom driver-specific commands.
-        /// This method will not overwrite existing commands for a specific name.
+        /// This method will not overwrite existing commands for a specific name, and will return <see langword="false"/>
+        /// in that case.
         /// </remarks>
-        internal bool TryAddAdditionalCommand(string commandName, CommandInfo commandInfo)
+        public bool TryAddCommand(string commandName, CommandInfo commandInfo)
         {
             if (string.IsNullOrEmpty(commandName))
             {