Remote control "Open remote files" should allow opening remote GeoJSON, GPX etc.

[NeatNit]

I want to instruct JOSM to load a geojson or GPX file from a remote URL. For an example use-case, PTNA ( ​https://wiki.openstreetmap.org/wiki/Public_Transport_Network_Analysis ) could load a bus trip's GPX file into JOSM in an instant. Right now this has to be downloaded and loaded manually with the "GPX-Download" button, as can be seen at: ​https://ptna.openstreetmap.de/gtfs/DE/single-trip.php?feed=DE-BW-bodo&release_date=&trip_id=ddb-90-M70-1-1-32-H-24-Special%23892-44-28

In another instance, I would like to load GeoJSON data from an ArcGIS query directly into JOSM. The query URL is in the format: ​https://gisn.example.com/arcgis/rest/services/IView2/MapServer/577/query?where=1%3D1&outFields=*&f=geojson - right now I can only do it by saving the result to a local file using a web browser and loading the file manually in JOSM.

The remote control preferences have a permission for "Open remote files", but it only seems to allow geotagged images and nothing else: ​https://github.com/search?q=repo%3AJOSM%2Fjosm%20ALLOW_WEB_RESOURCES&type=code

It would be amazing if this same functionality was extended to allow loading of other file/data types supported by JOSM.

Also, even this functionality is not documented - the API description of /open_file makes no mention of its ability to load URLs, and only mentions local files:

/open_file — opens a local file in JOSM
mandatory parameters: filename
examples:
/open_file?filename=/tmp/test.osm

However this seems to work: ​http://127.0.0.1:8111/open_file?filename=https://upload.wikimedia.org/wikipedia/commons/c/cd/London%2C_London_Eye_--_2016_--_4801.jpg (found by galen on Discord)

So this is a feature request to allow remote loading of more data file types, and also to more fully document the API endpoint. Thanks!

[galen8183]

load GeoJSON data from an ArcGIS query directly into JOSM

This is usually possible with the Open Location dialogue, however in this case the request URL uses f=geojson rather than format=geojson -- modifying the regex to accept f(?:ormat)?=geojson instead of strictly format=geojson should be sufficient for this issue

[NeatNit]

Opened a separate ticket for the issue raised by galen: #24270 as these are two separate issues (one is about remote control, the other is about open location)