external link for studies: when ICTR does not find the study

not always the link, using the ictr url and our primary identifier, works (i.e. ictr does not return any study but a generic page).
e.g.
https://trialsearch.who.int/Trial2.aspx?TrialID=2004-000012-13

while this works:
https://trialsearch.who.int/Trial2.aspx?TrialID=TCTR20241030016

to check if we should use another identifier for the link