Pydantic model validation upgrade

[Archento]

Prerequisites

• I checked the documentation and made sure this feature does not already exist
• I checked the existing issues to make sure this feature has not already been requested

Feature

We want to upgrade uagents communication models to Pydantic V2 BaseModels as the current state leads to a inconsistent behaviour across the framework and supporting services.

The digest of communication models will change which makes this a "breaking" change.
To solve this problem we'll want to introduce a local lookup table that matches previous digests to the new ones for a prolonged transition period and to make sure that existing agents can seamlessly interact with new agents.

Additional Information (Optional)

No response

[Archento]

Turns out that this is not easily achieved and other teams or open source software stacks have equally failed to create some form of backwards compatibility between pydantic versions.
This leads us to the decision to introduce a breaking change without the backwards compatibility in place so you need to update your agents to be able to communicate with agents in Agentverse.ai or other agents in the future.