Add campaign period to governance process

# Background

Jen remarks

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In the election cycle currently we have:

Announcing period - 9 days (not sure of the exact number of days really)
Voting period - 3 days
Revealing period - 3 days

Is it technically possible to add “campaign period” after the announcing period and allot 1 or 2 days for it (get these days from announcing period)? In this campaign period, we can use the time to hold meetings/debates and for the candidates to campaign their candidacies.
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# Proposal

Add new council period as stated. This would be a very complex change across runtime, QN and apps, tests, etc. so would require a lot of time to execute on.