FEAT: added simple mobileprovision codec,

which can be used to load Apple's mobile provisioning files as a string for examination (without need to use Apple's tools).
```
>> print load %some.mobileprovision
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
        <key>AppIDName</key>
        <string>My App</string>
        <key>ApplicationIdentifierPrefix</key>
        <array>
...
```

src/mezz/codec-der.r

@@ -324,3 +324,16 @@ register-codec [
 
 	verbose: 0
 ]
+
+register-codec [
+	name:  'mobileprovision
+	title: "Apple's mobileprovision file"
+	suffixes: [%.mobileprovision]
+	decode: function[data [binary!]][
+		try [
+			der: codecs/DER/decode data
+			result: to string! der/sequence/cs0/sequence/sequence/cs0/2
+		]
+		result
+	]
+]