Limit number of active proposals by a member

[mattsse]

Issue summary

There are no limits on how many proposals can be submitted. To mitigate spam a threshold is required that caps the number of active proposals by a single Account

Possible solution:

• [ ] extend the Proposal type with the submitter.
• [ ] refactor the Members map to also include a counter of submitted and active proposals
• [ ] increase proposal counter if a new proposal was submitted
• [ ] decrease proposal counter if the proposal was closed

Other information and links

• 372

[mattsse]

this feature is currently not required as it goes against the expected usage of proposal submissions