Figure out a way to use local user files as sources

[yamalight]

It's quite common use case when people want to use their existing file as input to transform and visualise it. Figure out how to do it.

Possible straight up solution: allow attaching files to components, store file as blob in db, then pass them as input to the given component.

[yamalight]

Another solution: user filespace that is linked to runner and can be accessed by the components using /data or something similar.
Easier to limit and control space. Can be tricky to handle access control from components.