Introduce concept of CardProfileAddon

We have a strict "one CardProfile per card" rule.  For a modern UICC
without legacy SIM support, that works great, as all applications
have AID and ADF and can hence be enumerated/detected that way.

However, in reality there are mostly UICC that have legacy SIM, GSM-R
or even CDMA support, all of which are not proper UICC applications
for historical reasons.

So instead of having hard-coded hacks in various places, let's introduce
the new concept of a CardProfileAddon.  Every profile can have any
number of those.  When building up the RuntimeState, we iterate over the
CardProfile addons, and probe which of those are actually on the card.
For those discovered, we add their files to the filesystem hierarchy.

Change-Id: I5866590b6d48f85eb889c9b1b8ab27936d2378b9

pySim/profile.py

@@ -88,6 +88,7 @@ class CardProfile:
                 shell_cmdsets : List of cmd2 shell command sets of profile-specific commands
                 cla : class byte that should be used with cards of this profile
                 sel_ctrl : selection control bytes class byte that should be used with cards of this profile
+                addons: List of optional CardAddons that a card of this profile might have
         """
         self.name = name
         self.desc = kw.get("desc", None)
@@ -97,6 +98,8 @@ class CardProfile:
         self.shell_cmdsets = kw.get("shell_cmdsets", [])
         self.cla = kw.get("cla", "00")
         self.sel_ctrl = kw.get("sel_ctrl", "0004")
+        # list of optional addons that a card of this profile might have
+        self.addons = kw.get("addons", [])
 
     def __str__(self):
         return self.name
@@ -161,3 +164,34 @@ class CardProfile:
                 return p()
 
         return None
+
+    def add_addon(self, addon: 'CardProfileAddon'):
+        assert(addon not in self.addons)
+        # we don't install any additional files, as that is happening in the RuntimeState.
+        self.addons.append(addon)
+
+class CardProfileAddon(abc.ABC):
+    """A Card Profile Add-on is something that is not a card application or a full stand-alone
+    card profile, but an add-on to an existing profile.  Think of GSM-R specific files existing
+    on what is otherwise a SIM or USIM+SIM card."""
+
+    def __init__(self, name: str, **kw):
+        """
+        Args:
+                desc (str) : Description
+                files_in_mf : List of CardEF instances present in MF
+                shell_cmdsets : List of cmd2 shell command sets of profile-specific commands
+        """
+        self.name = name
+        self.desc = kw.get("desc", None)
+        self.files_in_mf = kw.get("files_in_mf", [])
+        self.shell_cmdsets = kw.get("shell_cmdsets", [])
+        pass
+
+    def __str__(self):
+        return self.name
+
+    @abc.abstractmethod
+    def probe(self, card: 'CardBase') -> bool:
+        """Probe a given card to determine whether or not this add-on is present/supported."""
+        pass