[BUG] metadata.[showDescription] not working programatically

## Description
When programmatically adding 'showDescription = true' to the metadata of a custom activity, the nodes in the workflow designer do not display the description. However 'showDescription' under the common properties is checked. Further more, interacting with any custom activity card 'showDescription' checkbox has no effect, yet system activity cards function as normal. Am i implementing it correctly?

## Steps to Reproduce
```
var myDoActivity = new DoActivity
myDoActivity.Metadata = new Dictionary
{
["showDescription"] = true
};
```
```
public class DoActivity : CodeActivity
{
protected override async ValueTask ExecuteAsync(ActivityExecutionContext context)
{
Console.WriteLine("Doing activity...");
context.TransitionTo(ActivityStatus.Completed);
}
}
```

im using this docker image: elsaworkflows/elsa-studio-v3:latest
```
docker pull elsaworkflows/elsa-studio-v3:latest
docker run -t -i -e ASPNETCORE_ENVIRONMENT='Development' -e HTTP_PORTS=8080 -e ELSASERVER__URL=https://localhost:7036/elsa/api -p 14000:8080 elsaworkflows/elsa-studio-v3:latest
```