Add autocomplete for location field

[MartinKolarik]

Referencing US states and cities requires jsdelivr/globalping#629, and doesn't work at the moment. Closes #537.

Also fixes displaying error messages for the location field and hides the map in case of errors that are shown below it, as those were easy to miss otherwise.

TODO:

• If two values are present, autocomplete should not delete the first one.
• Improve + to work with networks and tags.
• Try to add a "no results" message.

[jimaek]

I love how it works as a location search, but it makes look like that's all we support. Since it doesn't pick up networks, tags and so on. Plus it doesn't understand the combo + feature. So as a new user I might think it's not even an option. We would have to hope users read the tooltip and don't get discouraged by the auto complete.

There must something we can do, maybe add hints inside it?

[MartinKolarik]

Not sure how to make it clearer than this, it's the exact reason that message is there:

Also:

• network names are supported, only AS numbers are not - don't expect people would use them without copy/pasting,
• system tags are supported (user tags not as they'd add too much noise, I think),
• + is supported across cities/countries/states (it's even used by the autocomplete itself if you select cities).

[MartinKolarik]

• is supported (it's even used by the autocomplete itself if you select cities for example)

I guess you meant a combination of network/tag and a place? That it indeed doesn't work but I think I can make that work too.

[jimaek]

Yes a combo, that's what I use the most of all combos.

How about showing a message when no matches are found? That's when it's needed most. Maybe show the contents of the tooltip to make it clear that lack of results doesn't mean it's not going to work

[MartinKolarik]

How about showing a message when no matches are found? That's when it's needed most. Maybe show the contents of the tooltip to make it clear that lack of results doesn't mean it's not going to work

The tooltip message won't directly help, but I was thinking in that direction, too, now. Will try to write something to show in that case.

[MartinKolarik]

@jimaek check the + handling behavior now.