Fix stack access with advanced permissions - Take 2

[mlocati]

This pool 😉 request is an alternative to #7029.
Here I'm trying to implement what @aembler suggested.

WARNING it's not yet done, I'm currently facing a big issue, as described below.

Let's assume that we configure the stack with the following page permissions:

• if we don't specify these lines, the resulting area permissions are the following ones (the user can't add blocks to the stack):

  

• if we specify these lines, the resulting area permissions are the following ones (the user can add blocks to the stack):

  

  BUT, since the permission "can add block to page" is not implemented, we have this error here:

  Call to undefined method
  Concrete\Core\Permission\Access\ListItem\PageListItem::getBlockTypesAllowedPermission()
  

  ...which I really don't know how to solve 😢

[mlocati]

This PR should be ready to be reviewed/merged: the main issue is #7086

[mlocati]

I can confirm that everithing works.

This pull request is still needed because with it:

• we consistently check the permissions when handling stacks
• we check if a user can add a localized version of a stack
• we show only the allowed operations in the /dashboard/blocks/stacks dashboard page
• we enable the editing UI for stacks even when users have access only to a stack

Bonus tracks:

• use STACKS_LISTING_PAGE_PATH instead of '/dashboard/blocks/stacks'
• minor code cleanups
• show the correct name of the object type when displaying permissions inheritance ("This page inherits its permissions from" vs "This stack inherits its permissions from" vs "This global area inherits its permissions from")

I can of course close this PR and open different PRs...

[mlocati]

PS: I applied this PR to one of our production sites and everything seems to work fine.