[DONE] Entity-level permissions

[cannibalflea]

@Chr1sG I understand the limitations. As @Oshyan pointed out, I guess the options we are suggesting (either having conditional control over fields and/or multiple layouts) would be half measures from a permission-perspective but they would also have other useful benefits. So they can be suggested as possible workarounds (along with separate dedicated database as @mdubakov indicated) each with their own limitations, so creators can choose based on their needs. For example, in many cases, hiding or locking fields is not so much a matter of security but convenience/user experience.