New matrix-send-location node publishes m.location events using
matrix-js-sdk's makeLocationContent helper, so the wire format matches
Element's "Share my location". Per-message inputs are typed inputs
(msg / flow / global / num / str), defaulting to the obvious msg.*
names.
matrix-receive's m.location handler now also sets msg.latitude,
msg.longitude, msg.altitude, msg.description, msg.assetType, and
msg.timestamp on the output (additive - msg.geo_uri / msg.payload are
unchanged), so a Receive node wired straight into Send Location resends
a byte-equivalent event.
Help docs in both nodes updated.
