Include sendcsv parameter for email alert action

[AndreiBanaru]

Is your feature request related to a problem? Please describe.
Allow the results to be attached as CSV when this option is enabled for the email alert action.

Describe the solution you'd like
When the sendcsv key is defined as 'true':

deployment:
  alert_action:
    email:
      sendcsv: 'true'

, then it's set through the jinja2 template:

{% if detection.deployment.alert_action.email.sendcsv %}
action.email.sendcsv = 1
{% endif %}

Describe alternatives you've considered
We can of course set it through the Spunk UI or REST API, but the preference is to use DaC as much as possible.

Additional context
N/A