Possibility of Proposal to get cancelled before creation - Medium Severity

[olahfemi]

Description
The proposalcancel() function can allow an admin to cancel a proposalId before creation of such proposal, as there are no check to confirm that an IdPropsal have actually been proposed before giving the authourity to admin to cancel it, this implies that if an Admin mistakenly pass an Id which does not exist in the proposal for cancellation, the proposal will get cancel ahead of creating such proposal.

Context
GovernanceFacet.sol

Recommendation
Check that an Id proposal have actually been created before allowing cancellation because a proposal that has been cancelled cannot be revoked as there is no provision for a cancel proposal to be active anymore.