🦋 Remove POS role and replace it with an additional role type

[Tirodem]

Today POS role & features are linked to this specific role :

But :

• we have first feedback of people making admin on their POS computeur and switching account is annoying
• POS shared account is not liked by beBOP owners with employees for security purpose
• some features are confused by employee vs POS configuration - Manage basket addition from Alias #382 #1021 (comment)

My proposition :

• remove the POS role
• on ARM role configuration, add a "Has POS" selector yes / no
  
• on employee role configfuration, add a "Has POS" selector yes / no
  

If a role has "Has POS" = true, employee with this role have "Has POS" = true and input is disabled.
If a role has "Has POS" = false, employee with this role have "Has POS" = false, input is enabled, and can be set to yes (that way a non-specific POS role can access to POS specific features)