feat(adminui): DriverTagPicker modal + 9 static address builders

- DriverTagPicker shell: modal chrome + per-driver picker body
  rendered as ChildContent.
- 9 picker bodies (Modbus/AbCip/AbLegacy/S7/TwinCat/FOCAS/
  OpcUaClient/Galaxy/Historian.Wonderware). 5 have computed
  builder logic + unit tests; 4 are free-text passthroughs
  (live browse for OPC UA + Galaxy is a documented follow-up).
- Each typed driver page gets a "Pick address" button that opens
  the modal with the matching body. Picked address surfaces in
  the modal footer for manual copy — no JS interop in v1.

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Drivers/Pickers/AbLegacyAddressBuilder.cs

@@ -0,0 +1,12 @@
+namespace ZB.MOM.WW.OtOpcUa.AdminUI.Components.Shared.Drivers.Pickers;
+
+/// <summary>
+/// Pure static helper that converts AB Legacy PLC file-type + file-number + element
+/// into the canonical address string (e.g. N7:0).
+/// Extracted so unit tests can call it without bUnit.
+/// </summary>
+public static class AbLegacyAddressBuilder
+{
+    public static string Build(string fileType, int fileNumber, int element)
+        => $"{fileType}{fileNumber}:{element}";
+}