Change compactitemize to also use triangles

Someday I wanted to use both a regular itemize enrivonment as well as a compactitemize environment for space reasons, but discovered that they are differently represented (the former uses triangles to the right, while the latter uses bullets).

For the other types of environments (description, enumerate) both the compactified and the original version use the same symbol. Are there any deeper reasons for the bullet symbol? Otherwise, I suggest to change it to the right-directed triangle for consistency.