Add states for Organisations

[catileptic]

The elections that would have required this modification have been called off. Please do not attempt to solve this Issue.

We're keeping it open in order to server as a reminder of the changes we have planned for.

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Due to the fact that the same platform will be used across multiple election rounds, the states in which an organisation / elector can exist should be updated:

• Pending approval
• Eligible to vote
• Ineligible to vote
• Disabled
• Rejected

The mechanisms through which an org. transitions between these states is a work in progress with @overeha