Add styling to floor plans in visualizer

[mreveil]

Is your feature request related to a problem? Please describe.
This is an enhancement of the visualizer

Describe the solution you'd like
Implement support to apply different styling options to the map shown in the visualizer widget. For example, change the width and color of walls, change the color of specific spaces, change the representation used for people (e.g. icons, or emojis), etc. This will require the ability to uniquely identify all path elements in SVG floorplan files and apply unique styling to them in a way similar to CSS.

• Assign background color to each space independently (space boundaries should be provided)
• Change width and color of walls
• Use icon or emoji (image file in jpg or svg format) to represent people. Handle zooming and coloring as well.
• Load all the styling from CSS files that can be changed programmatically.

Describe alternatives you've considered

Additional context
This link contains some details on styling of SVG elements: https://css-tricks.com/svg-properties-and-css/