bts: Type Definition + Template for SI3; Send SI3 at start of test

The BTS needs some of the SI3 parameters like BS_AG_BLKS_RES for
internal computations, so make sure we send it after the connection
has been established.

Change-Id: I5dc3724f79e669f52593cd776806d84b4dd4bf5c
diff --git a/library/L3_Templates.ttcn b/library/L3_Templates.ttcn
index d3e021d..a614122 100644
--- a/library/L3_Templates.ttcn
+++ b/library/L3_Templates.ttcn
@@ -2093,6 +2093,8 @@
 	return f_concat_pad(12, '49123'H, suffix);
 }
 
+external function enc_MobileIdentityLV(in MobileIdentityLV si) return octetstring
+	with { extension "prototype(convert) encode(RAW)" };
 
 
 }