[ntuple] Move column index to the front of name string

This is an attempt to make Speedscope render columns in similar colors,
so they are visually distinguishable from fields.

Speedscope does not allow explicit control over frame colors, but it
appears to generate them based on the first characters of each string.
This behavior was discovered through trial and error, is not officially
supported and may still be improvable.

Author: albfsg

tree/ntupleutil/src/RNTupleInspector.cxx

@@ -670,8 +670,8 @@ void ROOT::Experimental::RNTupleInspector::PrintSchemaProfile(ESchemaProfileForm
          std::size_t columnSize = columnInfo.GetCompressedSize();
 
          SpeedscopeFrame columnSpeedscopeFrame;
-         columnSpeedscopeFrame.fPrimaryString = tupleDescriptor.GetQualifiedFieldName(fieldDescriptor.GetId()) +
-                                                " [col#" + std::to_string(columnDescriptor.GetPhysicalId()) + "]";
+         columnSpeedscopeFrame.fPrimaryString = "[col#" + std::to_string(columnDescriptor.GetPhysicalId()) + "]" +
+                                                tupleDescriptor.GetQualifiedFieldName(fieldDescriptor.GetId());
          columnSpeedscopeFrame.fSecondaryString =
             ROOT::Internal::RColumnElementBase::GetColumnTypeName(columnDescriptor.GetType());
          columnSpeedscopeFrame.fOpeningPosition = positionCursor;

tree/ntupleutil/test/ntuple_inspector.cxx

@@ -887,9 +887,9 @@ TEST(RNTupleInspector, SchemaProfile)
    "shared":{
       "frames":[
          { "name":"float1", "file":"Type: float, Size: 40B" },
-         { "name":"float1 [col#0]", "file":"Type: SplitReal32, Size: 40B" },
+         { "name":"[col#0]float1", "file":"Type: SplitReal32, Size: 40B" },
          { "name":"int", "file":"Type: std::int32_t, Size: 40B" },
-         { "name":"int [col#1]", "file":"Type: SplitInt32, Size: 40B" }
+         { "name":"[col#1]int", "file":"Type: SplitInt32, Size: 40B" }
       ]
    },
    "profiles":[