SUMMARY
when opening a clip to add to a project, if its path is prepended with file:// it will say the file wasn't found

STEPS TO REPRODUCE
1. Copy a file with a file manager (like dolphin)
2. Click add click inside kdenlive
3. Paste the file into the textbox

OBSERVED RESULT
Kdenlive will say "file not found"

EXPECTED RESULT
For kdenlive to either automatically remove the file:/ or to be able to handle it regardless

SOFTWARE/OS VERSIONS
KDE Plasma Version: 5.20.3
KDE Frameworks Version: 5.76.0
Qt Version: 5.15.2

ADDITIONAL INFORMATION
I think it'd improve the workflow if we could just copy files from dolphin and paste them into kdenlive and have kdenlive be able to use the path to add it, right now it requires users to manually remove the file:/ from the start so that kdenlive is able to add the file.