AMI_Function: Match field keys in case insensitive way

As per [1], "Keys are case insensitive".

[1] https://docs.asterisk.org/Configuration/Interfaces/Asterisk-Manager-Interface-AMI/AMI-v2-Specification/

Change-Id: I9080f617c4e7272b9dd67d616069ac9350411f3c
diff --git a/asterisk/AMI_Functions.ttcn b/asterisk/AMI_Functions.ttcn
index b70e0ee..c1211a9 100644
--- a/asterisk/AMI_Functions.ttcn
+++ b/asterisk/AMI_Functions.ttcn
@@ -84,22 +84,22 @@
 ts_AMI_Field_Registration(template (value) charstring val) := ts_AMI_Field(AMI_FIELD_REGISTRATION, val);
 
 template (present) AMI_Field
-tr_AMI_Field_Action(template (present) charstring val := ?) := tr_AMI_Field(AMI_FIELD_ACTION, val);
+tr_AMI_Field_Action(template (present) charstring val := ?) := tr_AMI_Field(pattern @nocase AMI_FIELD_ACTION, val);
 template (present) AMI_Field
-tr_AMI_Field_ActionId(template (present) charstring val := ?) := tr_AMI_Field(AMI_FIELD_ACTION_ID, val);
+tr_AMI_Field_ActionId(template (present) charstring val := ?) := tr_AMI_Field(pattern @nocase AMI_FIELD_ACTION_ID, val);
 template (present) AMI_Field
-tr_AMI_Field_Username(template (present) charstring val := ?) := tr_AMI_Field(AMI_FIELD_USERNAME, val);
+tr_AMI_Field_Username(template (present) charstring val := ?) := tr_AMI_Field(pattern @nocase AMI_FIELD_USERNAME, val);
 template (present) AMI_Field
-tr_AMI_Field_Secret(template (present) charstring val := ?) := tr_AMI_Field(AMI_FIELD_SECRET, val);
+tr_AMI_Field_Secret(template (present) charstring val := ?) := tr_AMI_Field(pattern @nocase AMI_FIELD_SECRET, val);
 template (present) AMI_Field
-tr_AMI_Field_Response(template (present) charstring val := ?) := tr_AMI_Field(AMI_FIELD_RESPONSE, val);
+tr_AMI_Field_Response(template (present) charstring val := ?) := tr_AMI_Field(pattern @nocase AMI_FIELD_RESPONSE, val);
 /* Extensions: */
 template (present) AMI_Field
-tr_AMI_Field_Registration(template (present) charstring val := ?) := tr_AMI_Field(AMI_FIELD_REGISTRATION, val);
+tr_AMI_Field_Registration(template (present) charstring val := ?) := tr_AMI_Field(pattern @nocase AMI_FIELD_REGISTRATION, val);
 
 
 template (present) AMI_Field
-tr_AMI_Field_ResponseSuccess := tr_AMI_Field(AMI_FIELD_RESPONSE, "Success");
+tr_AMI_Field_ResponseSuccess := tr_AMI_Field(pattern @nocase AMI_FIELD_RESPONSE, "Success");
 
 
 /***********************