Use generated serializers for QueryVal serialization

[pnwpedro]

Description

• Use DynamicSerializer as default for type serializers
• Generate a type serializer for QueryVal.Serialize()
• Implement Serialize for all StructSerializers

Motivation and context

• We can now implement Serialize for each type serializer with smaller PRs
• Prepares for the addition of a registry where users can call Serializer.Registry.Add(type, serializer) to be used in the serialize/deserialize paths.

How was the change tested?

• Existing tests pass

Screenshots (if appropriate):

Change types

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (backwards-incompatible fix or feature)

Checklist:

• My code follows the code style of this project.
• My change requires a change to Fauna documentation.
• My change requires a change to the README, and I have updated it accordingly.