Create a new feature to add coordinate markers with QIDs, similar to the existing feature to add geoshapes by QID

• Syntax to be the same, except called geopoint T305822
• Allows adding one QID or multiple

Example:

{
  "type": "ExternalData",
  "service": "geopoint",
  "ids": "Q1218, Q801"
}

Documentation:

• The actual coordinate is pulled from Wikidata. See T304859.

Open questions:

• When multiple coordinates exist for one QID, display all. Any message to users needed? T306540
• Can markers automatically display information about the item? Design to investigate what should be shown. T307707
• Is there a maximum number of QIDs that can be used?