Unify all wrappers on the MainVoting plugin

[brickpop]

Changes:

• The MemberAccess plugin now acts as a pure helper of the MainVoting plugin
  • proposeAddMember() on the MemberAccess is only callable on the MainVoting plugin
• The GovernancePluginsSeup grants an additional permission
  • The MainVoting plugin can propose on the MemberAccess plugin
  • MainVoting plugin is initialized with the address of MemberAccess plugin
• proposeAddMember() is approved on a separate plugin, because the approval rules are different from the rest of proposals
• Removing isMember and isEditor() from MemberAccess plugin
• MultisigSettings no longer stores the address of the MainVoting plugin
• MultisigSettingsUpdated only has one parameter now
• Removing unused custom errors
• Removing createProposal() from MemberAccess plugin
• Added the custom error ProposalCreationForbiddenOnSameBlock()

[CLAassistant]

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✅ brickpop
❌ Jør∂¡

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