docs: backfill XML documentation across 756 files

Adds <summary>, <param>, <typeparam>, and <inheritdoc/> tags to public
members surfaced by commentchecker — resolves 5,847 of 5,869 issues
(99.6%) across three /fixdocs passes.

tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.IntegrationTests/DualEndpointTests.cs

@@ -23,6 +23,7 @@ public sealed class DualEndpointTests
     private const string NodeAUri = "urn:OtOpcUa.DualEndpoint.NodeA";
     private const string NodeBUri = "urn:OtOpcUa.DualEndpoint.NodeB";
 
+    /// <summary>Verifies that a client can read the ServerArray containing both redundant node URIs.</summary>
     [Fact]
     public async Task Client_reads_both_ApplicationUris_from_NodeA_ServerArray()
     {