Add index/offset accessors to Il2CppMetadata

Introduce utility accessors to Il2CppMetadata for retrieving entries by index or by offset. Adds methods for nested type indices, interface indices, property definitions, method definitions, and field definitions (both index- and offset-based), complementing existing range helpers and reducing manual index arithmetic when parsing metadata.

Author: Xpl0itR

LibCpp2IL/Metadata/Il2CppMetadata.cs

@@ -640,23 +640,40 @@ internal string ReadStringFromIndexNoReadLock(int index)
 
     public Il2CppParameterDefinition GetParameterDefinitionFromIndex(Il2CppVariableWidthIndex<Il2CppParameterDefinition> index) => parameterDefs[index.Value];
 
+    public Il2CppNestedTypeIndex GetNestedTypeIndicesFromIndex(Il2CppVariableWidthIndex<Il2CppNestedTypeIndex> index) => nestedTypeIndices[index.Value];
+
+    public Il2CppNestedTypeIndex GetNestedTypeIndicesFromOffset(Il2CppVariableWidthIndex<Il2CppNestedTypeIndex> startIndex, ushort offset) => nestedTypeIndices[startIndex.Value + offset];
+
     public IEnumerable<int> GetNestedTypeIndicesFromIndexAndCount(Il2CppVariableWidthIndex<Il2CppNestedTypeIndex> index, int count) => nestedTypeIndices.Skip(index.Value).Take(count).Select(n => n.Value);
 
+    public Il2CppVariableWidthIndex<Il2CppType> GetInterfaceIndicesFromIndex(Il2CppVariableWidthIndex<Il2CppInterfaceOffset> index) => interfaceIndices[index.Value];
+
+    public Il2CppVariableWidthIndex<Il2CppType> GetInterfaceIndicesFromOffset(Il2CppVariableWidthIndex<Il2CppInterfaceOffset> startIndex, ushort offset) => interfaceIndices[startIndex.Value + offset];
+    
     public IEnumerable<Il2CppVariableWidthIndex<Il2CppType>> GetInterfaceIndicesFromIndexAndCount(Il2CppVariableWidthIndex<Il2CppInterfaceOffset> index, int count) => interfaceIndices.Skip(index.Value).Take(count);
 
     public Il2CppInterfaceOffset[] GetInterfaceOffsetsFromIndexAndCount(Il2CppVariableWidthIndex<Il2CppInterfaceOffset> index, int count) => interfaceOffsets.SubArray(index.Value, count);
 
+    public Il2CppPropertyDefinition GetPropertyDefinitionsFromIndex(Il2CppVariableWidthIndex<Il2CppPropertyDefinition> index) => propertyDefs[index.Value];
+
+    public Il2CppPropertyDefinition GetPropertyDefinitionsFromOffset(Il2CppVariableWidthIndex<Il2CppPropertyDefinition> startIndex, ushort offset) => propertyDefs[startIndex.Value + offset];
+    
     public Il2CppPropertyDefinition[] GetPropertyDefinitionsFromIndexAndCount(Il2CppVariableWidthIndex<Il2CppPropertyDefinition> index, int count) => propertyDefs.SubArray(index.Value, count);
 
     public Il2CppEventDefinition[] GetEventDefinitionsFromIndexAndCount(Il2CppVariableWidthIndex<Il2CppEventDefinition> index, int count) => eventDefs.SubArray(index.Value, count);
 
     public Il2CppMethodDefinition GetMethodDefinitionFromIndex(Il2CppVariableWidthIndex<Il2CppMethodDefinition> index) => methodDefs[index.Value];
+
+    public Il2CppMethodDefinition GetMethodDefinitionFromOffset(Il2CppVariableWidthIndex<Il2CppMethodDefinition> startIndex, ushort offset) => methodDefs[startIndex.Value + offset];
 
     public Il2CppMethodDefinition[] GetMethodDefinitionsFromIndexAndCount(Il2CppVariableWidthIndex<Il2CppMethodDefinition> index, int count) => methodDefs.SubArray(index.Value, count);
 
     public Il2CppGenericParameter GetGenericParameterFromIndex(Il2CppVariableWidthIndex<Il2CppGenericParameter> index) => genericParameters[index.Value];
 
     public Il2CppFieldDefinition GetFieldDefinitionFromIndex(Il2CppVariableWidthIndex<Il2CppFieldDefinition> index) => fieldDefs[index.Value];
+
+    public Il2CppFieldDefinition GetFieldDefinitionFromOffset(Il2CppVariableWidthIndex<Il2CppFieldDefinition> startIndex, ushort offset) => fieldDefs[startIndex.Value + offset];
+
     public Il2CppFieldDefinition[] GetFieldDefinitionsFromIndexAndCount(Il2CppVariableWidthIndex<Il2CppFieldDefinition> index, int count) => fieldDefs.SubArray(index.Value, count);
 
     public string GetStringLiteralFromIndex(uint index)