feat(adminui): author + configure the Sql driver in /raw

The read-only Sql driver's runtime factory/probe and tag-side editors were
wired, but the AdminUI could not author the DRIVER: the /raw "New driver" type
list, the DriverConfigModal switch, and the legacy identity dropdown all omitted
Sql, and no SqlDriverForm existed. Live-driving the AdminUI surfaced this.

- Add SqlDriverForm.razor over the SqlDriverConfigDto shape: Provider
  (SqlServer-only in v1), required connectionStringRef (an env-var NAME, not a
  connection string — label is explicit), optional poll/operation/command
  timeouts, maxConcurrentGroups, nullIsBad. Enums serialize by NAME via
  JsonStringEnumConverter; a connection-string literal can never be authored
  (no such field is collected); rawTags (composer-owned) + allowWrites (inert,
  read-only v1) are never emitted.
- Wire Sql into DriverConfigModal switch, RawDriverTypeDialog type list, and
  DriverIdentitySection legacy dropdown.
- Add SqlDriverFormContractTests: the exact JSON the form emits constructs a
  driver through the real factory, missing connectionStringRef is rejected, and
  provider round-trips as the "SqlServer" name (never an ordinal).

Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Drivers/DriverConfigModal.razor

@@ -57,6 +57,9 @@
                             case DriverTypeNames.Galaxy:
                                 <GalaxyDriverForm @bind-DriverConfigJson="_driverConfigJson" @bind-ResilienceConfig="_resilienceConfig" />
                                 break;
+                            case DriverTypeNames.Sql:
+                                <SqlDriverForm @bind-DriverConfigJson="_driverConfigJson" @bind-ResilienceConfig="_resilienceConfig" />
+                                break;
                             default:
                                 <div class="alert alert-warning">No typed config form for driver type <span class="mono">@_driverType</span>.</div>
                                 break;