Support evolving the document model stored in relational columns

Hi there,
looking for an example on:

**How to update/change with migration the exitsing data in the JsonColumns so I don't run into not exsiting paths exception?**

Just saw dotnefconf 2023... great job, instantly playing a bit around how it behaves with model changes over dev/app lifetime.

Creation worked fine...

```
public class BlogLinks
{
public string? Url { get; set; }
public string? Text { get; set; }
}
```

After model change

```
public class BlogLinks
{
public string? Url { get; set; }
public string? Text { get; set; }
public string? SomeThingNew { get; set; }
}
```
the `dotnet ef database update` was successful but did not any change to the data JSON in the JSON Columns,
like adding the new Property of Model eg `{ SomeThingNew : null } `

So although the model in C# knows the property `SomeThingNew `
adding some info throws "**Property cannot be found on the specified JSON path**"


Adding new one is no problem:


So it's just how is the EF8 Core way of doing this migration update on existing models in json data right.

Cheers Otto.