Alerts: Trails lat/long

[shua123]

• For trail system alerts, have ability to enter a lat/lon coordinate.
• Output lat/lon coordinate somehow in alerts json

[shua123]

Add validations for lat/long:

• If one exists, make sure both exist
• Check values to make sure they fall within county bounding box.

[shua123]

@versatilehuman With our current setup of trail system + segments impacted, what is the current importance/priority of custom lat/long option? Do we still need this now or should we hold off to see use/feedback on current form?

[versatilehuman]

@shua123 With the way this has evolved I'd say we can hold off on this feature. "Trail segments ABC near XYZ locations" is pretty good and we can always add further description. How we would even display or link to a lat/long is still an open question. So unless we get some strong feedback that what we are giving users is not enough, I think we can hold off.