feat(historian): #691 HistoryRead-Raw ReturnBounds — Part 11 bounding values on every backend

The node manager composes the start/end bounds from each backend's existing raw
reads (one authority, HistoryBounds): at-or-before = a capped reverse read
(native, or ReverseRawReader's walk-back on a forward-only backend — never
AVEVA's synthetic boundary row), at-or-after = a capped forward read. Bounds
count toward NumValuesPerNode, the start bound leads the first page, the end
bound ends the last (carried in the continuation point). Missing bound =
Bad_BoundNotFound (null, at the bound time; one-sided reads ±1 s from the
previous value, Table 1 footnotes a/b). A modified read with ReturnBounds is
Bad_InvalidArgument (Part 11 6.5.3.3).

The .NET SDK's ReadRawModifiedDetails defaults ReturnBounds to TRUE; the
existing tests built details without setting it and now set it false.
Oracle: every row of Part 11 Table 1 over three backend shapes, plus paging
concatenation, ties, Bad bounds, microsecond truncation; conformance pins the
lookup primitives on SqlServer + QuestDB.

tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.Tests/NodeManagerHistoryReadPagingTests.cs

@@ -967,6 +967,7 @@ public sealed class NodeManagerHistoryReadPagingTests : IDisposable
 
         var details = new ReadRawModifiedDetails
         {
+            ReturnBounds = false,
             StartTime = start,
             EndTime = end,
             NumValuesPerNode = max,
@@ -1000,6 +1001,7 @@ public sealed class NodeManagerHistoryReadPagingTests : IDisposable
             new RequestHeader(), secureChannelContext: null, RequestType.HistoryRead, identity: null);
         var details = new ReadRawModifiedDetails
         {
+            ReturnBounds = false,
             StartTime = Epoch, EndTime = Epoch.AddHours(1), NumValuesPerNode = 100, IsReadModified = false,
         };
         var nodesToRead = new List<HistoryReadValueId> { new() { NodeId = nodeId, ContinuationPoint = cp } };