Add new permissionsProvider_getGrantedPermissions RPC

[V00D00-child]

Description

Expose a new RPC method permissionsProvider_getGrantedPermissions to be used by Metamask clients to retrieve granted permissions for all sites.

Related issues

Related to: Persisting Granted Permissions with MM Profile Sync
Required by(MM Extension): Feat/gator permissions revoke UI
Required by(MM Core): feat: add gator permissions controller

Manual testing steps

Exiting functionally should behave as expected. To test the new RPC method, a local build of MaskMeta is required with a request made to gator-snap. See code snippet below for more context:

// Make call to gator-snap new RPC methods directly inside MetaMask extension, the method is only accessible by metamask clients
// Code below needs to be run in the context of the MetaMask extension
 const sampleResponse = (await handleSnapRequest({
          snapId: 'local:http://localhost:8082/', // this would be @metamask/gator-permissions-snap in prod
          origin: 'metamask',
          handler: 'onRpcRequest',
          request: {
            jsonrpc: '2.0',
            method: 'permissionsProvider_getGrantedPermissions',
          },
   })) as { id: string };
  console.log('sampleResponse(to gator-snap):', sampleResponse);

Pre-merge author checklist

• I've followed MetaMask 7715 Permissions Snaps Contributor Docs and MetaMask 7715 Permissions Snaps Coding Standards.
• I've completed the PR template to the best of my ability
• I’ve included tests if applicable
• I’ve documented my code using JSDoc format if applicable

Pre-merge reviewer checklist

• I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
• I confirm that this PR addresses all acceptance criteria described in the ticket it closes and includes the necessary testing evidence such as recordings and or screenshots.

[MoMannn]

LGTM