feat(integrations): new dispatcher mode

[migmartri]

Updates the dispatcher and sdk to enable aggregated mode, more on that here #205

The summary of the change would be

• Now an attached integration gets called only once, with all the materials in their parameters.
• There is no need to indicate in the plugin that you want to receive the attestation envelope, you'll always get that.

This makes the execution mode conceptually easier to understand and explain. An integration will be called each time an attestation is received, and it might contain some materials of the type you've subscribed to.

re: dispatcher changes

The code has been simplified by following a hydration pattern where we make a queue of possible dispatches go through a series of hydration steps, 1) initialize queue and with integration configurations from the DB, 2) add attestation and material information, 3) add chainloop metadata and 4) dispatch

This new mode enables developers for example to be able to send the materials they care alongside the attestation at once, see example of a discord POC below

Closes #205

[danlishka]

LGTM