Do not require event_timestamp for materialization #5624

Is your feature request related to a problem? Please describe.
Do not require event_timestamp for materialization

materialize shouldn't always require a timetsamp and the feature views shouldn't require a date to materialize as well.

Describe the solution you'd like
We should allow users to override with a flag --disable-event-timestamp should set the default timestamp for materilalization to datetime.now().

Describe alternatives you've considered
N/A

Additional context
Add any other context or screenshots about the feature request here.