Bug: Missing tests for Unicorn.Web

### Expected Behaviour

Unicorn Web is missing tests

### Current Behaviour

N/A

### Code snippet

```csharp
N/A
```

### Possible Solution

Implement tests such as those found here https://github.com/aws-samples/aws-serverless-developer-experience-workshop-dotnet/blob/develop/Unicorn.Web/ApprovalService.Tests/RequestApprovalFunctionTest.cs

### Steps to Reproduce

N/A

### Debugging logs

_No response_