Adds Session Authentication, and Refactor Authorisation

[Badgerati]

Description of the Change

• Adds a new "Session Authentication" method, which can be added using the new Add-PodeAuthSession
• Refactors the Authorisation functions to be in their own space, away from Auth. For example, Add-PodeAuthAccess is now Add-PodeAccess
• Access is not set at the Route level, not the Authentication level, making even more dynamic scenarios possible
• Authorisation is now its own separate middleware, away from Authentication
• Fixes Authorisation not working appropriately when sessions are being used
• Splits Add-PodeAccess into New-PodeAccessScheme and Add-PodeAccess - this works similar to the Auth New/Add functions

Related Issue

Resolves #1163

Examples

Start-PodeServer {
    Add-PodeEndpoint -Address * -Port 8085 -Protocol Http

    # setup access
    New-PodeAccessScheme -Type Role | Add-PodeAccess -Name 'TestRbac'
    New-PodeAccessScheme -Type Group | Add-PodeAccess -Name 'TestGbac'

    # merge access
    Merge-PodeAccess -Name 'TestMergedAll' -Access 'TestRbac', 'TestGbac' -Valid All
    Merge-PodeAccess -Name 'TestMergedOne' -Access 'TestRbac', 'TestGbac' -Valid One

    # setup basic auth (base64> username:password in header)
    New-PodeAuthScheme -Basic -Realm 'Pode Example Page' | Add-PodeAuth -Name 'Validate' -Sessionless -ScriptBlock {
        param($username, $password)

        # here you'd check a real user storage, this is just for example
        if ($username -eq 'morty' -and $password -eq 'pickle') {
            return @{
                User = @{
                    Name = 'Morty'
                    Roles = @('Developer')
                    Groups = @('Software', 'Admins')
                }
            }
        }

        return @{ Message = 'Invalid details supplied' }
    }

    # POST request to get list of users - there's no Access, so any auth'd user can access
    Add-PodeRoute -Method Post -Path '/users-all' -Authentication 'Validate' -ScriptBlock {
        Write-PodeJsonResponse -Value @{
            Users = @(@{ Name = 'Deep Thought' })
        }
    }

    # POST request to get list of users - only Developer roles can access
    Add-PodeRoute -Method Post -Path '/users-dev' -Authentication 'Validate' -Access 'TestRbac' -Role Developer -ScriptBlock {
        Write-PodeJsonResponse -Value @{
            Users = @(@{ Name = 'Leeroy Jenkins' })
        }
    }

    # POST request to get list of users - only users in the SOftware group can access
    Add-PodeRoute -Method Post -Path '/users-soft' -Authentication 'Validate' -Access 'TestGbac' -Group Software -ScriptBlock {
        Write-PodeJsonResponse -Value @{
            Users = @(@{ Name = 'Smooth McGroove' })
        }
    }

    # POST request to get list of users - only Developer role in the Admins group can access
    Add-PodeRoute -Method Post -Path '/users-dev-admin' -Authentication 'Validate' -Access 'TestMergedAll' -Role Developer -Group Admins -ScriptBlock {
        Write-PodeJsonResponse -Value @{
            Users = @(@{ Name = 'Arthur Dent' })
        }
    }

    # POST request to get list of users - either DevOps role or Admins group can access
    Add-PodeRoute -Method Post -Path '/users-devop-admin' -Authentication 'Validate' -Access 'TestMergedOne' -Role DevOps -Group Admins -ScriptBlock {
        Write-PodeJsonResponse -Value @{
            Users = @(@{ Name = 'Monkey D. Luffy' })
        }
    }
}