Add meter as a distance unit

[Anthony-Gaudino]

Problem
I'm trying to create a very small map, 8x8km, and the distance measurement tools don't have a meters option, making it difficult to measure distances. They appear as 0 in the interface.

Solution
Add meters as a distance unit.

Alternatives
One alternative is to display a floating point value, for example, 0.5km. If we could have both, meters and an option to display floating point distances it would be better.