Add dark mode to location sharing

### Your use case

#### What would you like to do?
Use dark theme in element including location sharing
#### Why would you like to do it?
not burn my eyes when viewing a shared location
#### How would you like to achieve it?
- is it svg? -> replace colors
- rendered on server? -> use server and api with dark mode support

### Have you considered any alternatives?

_No response_

### Additional context

_No response_

### Are you willing to provide a PR?

No

The issue names no files, tests, or entry points and leaves open whether location sharing is an SVG or server-rendered. Start by locating the location-sharing implementation and tracing how its colors are produced; done means shared locations display correctly in Element's dark theme, with the rendering approach agreed first.

Written by the indexing model from the issue text.