Added streaming selection option to events

[zarya]

Fixes #620

[zarya]

After merging this to production dont forget to update the previous talks that had recording with streaming since streaming is default False!

from program.models import Event
from program.models import EventProposal

Event.objects.filter(video_recording=True).update(video_streaming=True)
Event.objects.filter(video_recording=False).update(video_streaming=False)
EventProposal.objects.filter(allow_video_recording=False).update(allow_video_streaming=False)
EventProposal.objects.filter(allow_video_recording=True).update(allow_video_streaming=True)

[tykling]

we should check this with the content team before merging, what does @ahf say?

[tykling]

After merging this to production dont forget to update the previous talks that had recording with streaming since streaming is default False!

this PR should add a datamigration for this https://docs.djangoproject.com/en/5.2/topics/migrations/#data-migrations