[atlas] Excluding probes by user defined tag not working

Hello Yang, Stephane,

>> For example, I excluded user tag SDFJLKFWEO from measurement
>> 2312281, but probe 10240 was still selected.
> 
> I tried from the API and the results are strange. Some existing user
> tags are not recognized:

Indeed you've found something that we can and will improve, but in general
the system behaves as expected. Let me explain.

Users can tag their probes with anything they like, we have no restrictions
here. However, only the "approved" tags show up to other users, and only
these can be used in the measurement API (besides the system tags, but
that's not a part of this discussion).

Stephane used the API, which properly accepted the tag "home" but rejected
the tag "sdfjlkfweo". This is expected and the error was correct and
descriptive.

Yang discovered two small bugs in the UI:
* The tag suggestion feature should only offer approved tags -- but it
offers all of them at the moment. This is not a big problem, but also not
the desired behaviour.
* The measurement UI refuses to make a measurement with an unapproved tag
(in fact the underlying API does, as described above) -- but it fails to
warn the user about this, instead it shows the form again, with all data
pre-filled *except* the probe tag in question. If the user is not eagle-eyed
and submits the form again (with no apparent changes), the system happily
accepts this and makes a measurement, but without that tag
exclusion/inclusion clause.

Thank you for reporting these issues, they have already been fixed.

Regards,
Robert