Rename approved permission request `data` property

The `data` property of the approved permission request metadata (i.e. the second value in the returned tuple [here](https://github.com/MetaMask/core/blob/df1152f78aeae244fd946264bee9e013aad9bff5/packages/permission-controller/src/PermissionController.ts#L1916-L1924)) is actually only used for permission request side effects, and should be renamed `sideEffectData` or something similarly specific.

Start in packages/permission-controller/src/PermissionController.ts at the approved permission request metadata returned around lines 1916-1924. Find the related references to the `data` property and rename them consistently to a more specific name, then run the permission-controller tests; done means the metadata and its consumers use the clarified property name.

Written by the indexing model from the issue text.