Attach roles to spaces for child stacks to inherit

We have 200+ stacks that are set up in the pattern of spaces below. They need to have a common role attached to them and currently we have to attach the role to the stacks separately; this is easy enough to do but it does add 200+ role_attachment resources to our metadata stack. As we scale this pattern out to other roles and stacks spacelift runs will slow down due to large numbers of resources in opentofu.

- parent <-- have role here 
  - child_space1 
   - space_with_stacks_in <-- use role here 
  - child_space2 
   - space_with_stacks_in <-- use role here

Proposed solutions

• Allow roles to be attached to a space and child stacks inherit it

• Allow roles to be autoattach: in a similar way that rego policies can be