Rich Conditions - Use nlohmann::json

Based off of !3768 (merged) so diffs there will be seen here until that is merged.

Requires !3768 (merged), but does not have to be merged at the same time.

Det/LbDD4hep/include/LbDD4hep/ConditionAccessorHolder.h

@@ -10,6 +10,7 @@
 \*****************************************************************************/
 #pragma once
 
+#include <Core/Utils.h>
 #include <Gaudi/Property.h>
 #include <GaudiAlg/FixTESPath.h>
 #include <GaudiAlg/FunctionalUtilities.h>
@@ -21,7 +22,6 @@
 #include <GaudiKernel/detected.h>
 #include <Kernel/STLExtensions.h>
 #include <LbDD4hep/IDD4hepSvc.h>
-#include <LbDD4hep/utils.h>
 #include <any>
 #include <stdexcept>
 #include <type_traits>
@@ -140,8 +140,8 @@ namespace LHCb::Det::LbDD4hep {
           return T( cond );
         } else {
           using DT = std::decay_t<T>;
-          if constexpr ( std::is_same_v<DT, nlohmann::json> ) {
-            return utils::y2j( cond.get<YAML::Node>() );
+          if constexpr ( std::is_same_v<DT, YAML::Node> ) {
+            return LHCb::Detector::utils::json2yaml( cond.get<nlohmann::json>() );
           } else if constexpr ( !detail::PassAsAny<DT>::value ) {
             return cond.get<DT>();
           } else {