Add 'create * host permissions'

Problem/Motivation

I'd like to add the following permissions for to complete our establishment of access based on host:
create self host registration
create other users host registration
create anonymous host registration

'create self host registration' might seem strange as these are staff-type permissions, but I suspect that without it staff wouldn't be able to register themselves even if they could register others, which would be odd.

For these create permissions we will have to be cautious of 🐛 EntityAccessControlHandler::createAccess() and EntityAccessControlHandler::access() return false positive cache hits because it ignores context Needs work which makes it tricky to pass the host in the context. Let's start by posponing on that.

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes