More precise room list message preview for location sharing

### Your use case

### When someone else shares their (live) location
- keep the current behaviour: "Shared their location"
- if it's a live location: "Shared their live location". Possibly "Sharing their live location" if it can be determined that it is ongoing.

### When someone else shares another location that isn't their GPS position
- "Shared a location"

### When I share my location
- "You shared your location"
- "You shared your live location" (cf. their)

### When I share another location
- "You shared a location"

### Have you considered any alternatives?

This of course requires locations which are someone's position to be distinguishable from locations that are just some location they selected. If this isn't the case (and this might be on purpose e.g. for privacy) then it should always use "Shared a location"

### Additional context

_No response_

### Are you willing to provide a PR?

No

Start by locating the room-list message preview implementation and the location-sharing data used to distinguish a person's GPS position, another selected location, and live sharing. Check whether that distinction is available without compromising privacy, then verify the preview text for each sender and location type described in the issue.

Written by the indexing model from the issue text.