Add _updatedAt to some endpoints

[diegolmello]

In React Native app (probably native ones too), we need to fetch updated versions of custom emojis, permissions and settings when the app is opened.
We should have an _updatedAt (or updatedSince) param to return only updated records since last time the app was opened. This is already done on /api/v1/subscriptions.get.

This could be done in /api/v1/permissions.list, /api/v1/settings.public and /api/v1/emoji-custom.

[MarcosSpessatto]

• /api/v1/settings.public will be done when this PR is merged.
• /api/v1/permissions.list [NEW] Create new permission.listAll endpoint to be able to use updatedSince parameter #12748
• /api/v1/emoji-custom [NEW] Add query parameter support to emoji-custom endpoint #12754