filesystem: be case insensitive when selecting files by fid (HEX)

The file identifier (and allso application ids for ADFs), are
hexadecimal. We should be case insensitive when accepting hex
identifiers but file names should still be full matched.

Change-Id: Ibe283a108ddc9058af77c823b7222db555e1e0f6
Related: OS#4963

pySim/filesystem.py

@@ -580,6 +580,8 @@ class RuntimeState(object):
     def select(self, name, cmd_app=None):
         """Change current directory"""
         sels = self.selected_file.get_selectables()
+        if is_hex(name):
+            name = name.lower()
         if name in sels:
             f = sels[name]
             # unregister commands of old file