replace 'insight first-received' with 'plugin first-insight' in all dashboards

[shalom938]

we write 2 events
plugin first-insight
insight first-received

'insight first-received' is the old one, I added 'plugin first-insight' to make it same format as the other events like 'plugin first-assets', 'plugin first-issue'

replace in all dashboards 'insight first-received' with 'plugin first-insight' and stop sending the event 'insight first-received'

@doppleware can you replace in your dashboards?