[atlas] Retiring old ("legacy") UI pages and deprecated API calls

Dear all,

As part of the RIPE Atlas user interface renewal last year, we released 
a new measurement scheduling form and new probe and measurement lists. 
Since these changes the old pages were still accessible via changed 
URLs. By now the use of these pages all but disappeared, and we'll 
remove these from the UI in the coming weeks.

On a similar note, we'll also remove support for the API calls that took 
the form /api/v2/measurements/<TYPE>/ [*]. These have been deprecated 
for a long time, and since the last active user moved way most queries 
ending up here either come from the legacy pages or from hacking attempts.

[*] in fact this has effectively been an alias for 
/api/v2/measurements/?type=<TYPE> so no functionality is lost and it is 
trivial to change code that otherwise used these calls

Please reach out to us if you believe the legacy pages provided some 
functionality you think you'll miss so we can help you.

Regards,
Robert