feat: add version and description to definition

[josedonizetti]

1. Explain what the PR does

This PR is part of the work to support a v1 for GRPC, and also the #2870, because the new event structure won't have metadata, and instead static data from the event will come from the definition, so users will be able to query the grpc endpoint to get a definition, but there is two important fields missing from the definition:

• the event description
• the event version, which will be bumped if we change the Params, to inform users that the event schema changed

[josedonizetti]

@yanivagman @rafaeldtinoco what do you think? If you agree, I'll add a v1.0.0 version to every event defined on the core.

[yanivagman]

Yes, we can have all events versioned 1.0.0 at this point, and start following the semver semantics when updating the event:

1. Major field is bumped whenever some data the event used to have was changed (e.g. a field was renamed or removed)
2. Minor field is bumped whenever a non breaking change occurs (e.g. a new field was added to the event)
3. Patch field is bumped whenever something is changed in the way the event works internally (e.g. some bug was fixed in the code)

[yanivagman]

LGTM