Is there a built-in way to use the ["key"] indexer directly on Dictionary<string, object> in {{ ... }} expressions?

## Question / Feature Request

### Question

Is there a built-in way to use the `["key"]` indexer directly on `Dictionary` inside `{{ ... }}` expressions in **ClosedXML.Report** templates?

If not, are there recommended best practices for working with **nested dictionaries** (e.g. `Dictionary` containing other dictionaries) in templates?

---

### Sample data structure

```csharp
var items = new List>
{
new Dictionary
{
["id"] = 1,
["nodes"] = new Dictionary
{
["dynamic_node"] = new Dictionary
{
["availability"] = "Available"
}
}
}
};

No files, tests, or entry points are named. Start by inspecting how ClosedXML.Report evaluates {{ ... }} expressions and resolves Dictionary values, then compare that behavior with the nested dictionary sample. Done would require a documented or implemented way to access dictionary keys directly, including nested values.

Written by the indexing model from the issue text.