_emergency.json: Added check_date to fields

[jpds]

This is used by consumers such as OpenAEDMap.

[github-actions[bot]]

:bento: You can preview the tagging presets of this pull request here.

[tyrasd]

The check_date field has the "universal": true flag, and is therefore already available for all presets. This change would only affect AED features which do not have this tag already (then the universal field is "hidden" under "more fields"). Was is the intent of this PR to make it visible also if unset?

I'm just wondering why this preset should be handled differently compared to other features, like other emergency infrastructure like fire hydrants for example.

[jpds]

Was is the intent of this PR to make it visible also if unset?

Yes, I hadn't thought about the other emergency things - do I just move it into _emergency.json ?

[tyrasd]

good idea. let's try adding it to the generic _emergency.json preset