Give Imported draw objects their filename as layer title

[vagvaf]

Is your feature request related to a problem? Please describe.
When importing .kml (or .gpx -- haven't tested) into Hajk, the imported files use the imported datetime as "layer" title. This makes it hard for users to identify layers easily.

Describe the solution you'd like
I think it would be more convenient to use the file name instead (maybe in combination with the imported datetime)?

[Hallbergs]

Sounds like a good addition! Both the title and the name displayed would be nice.