revert [Blender_Kitsu] Remove metastrip filepath (#15)
Closes: TinyNick/blender-studio-tools#28
# Issue
Addon uses a filepath to import a blank file that metastrip relies on.
# Solution
- [x] Create a blank movie file without a filepath
- [x] Remove string property that contains metastrip filepath
### Old
![old_metastrip](/attachments/c35c64fc-d393-4d70-bc44-54bf819bd0c5)
### New
![new_metastrip](/attachments/1bed8f53-9157-421a-a6de-aea41662f171)
Co-authored-by: TinyNick <nick@blender.org>
Reviewed-on: #15