Add Config to set output serializer to System.Text.Json

#### What problem would the feature you're requesting solve? Please describe.

Solves the problem that input serializer and output serializer are different.
Function v3 uses `System.Text.Json` as input serializer and `Newtonsoft.Json` as output serializer. (#5299)

When sharing a Domain Model with an ASP.NET Core application, different serializers can cause compatibility issues.

#### Describe the solution you'd like

I need to change the output serializer to `System.Text.Json`.

#### Describe alternatives you've considered

There is a way to configure all applications to use `Newtonsoft.Json`.
However, it does not match the current trend of .NET Core.

#### Additional context

https://github.com/Azure/azure-functions-host/blob/v3.x/src/WebJobs.Script.WebHost/WebHostServiceCollectionExtensions.cs#L75

Start with src/WebJobs.Script.WebHost/WebHostServiceCollectionExtensions.cs around line 75 in the v3.x branch, then trace how input and output serializers are registered. Done means applications can configure the output serializer to System.Text.Json while preserving the existing input behavior and avoiding compatibility issues with shared ASP.NET Core domain models.

Written by the indexing model from the issue text.