fix: open files via double-click & cli args

[faselbaum]

Proposed Changes

Short description of the changes:

• changed the way how file open requests coming from the os layer are handled

Dev Notes

• this is a hotfix for the distributed executables
• ignore error message 'use strict' popping up when opening alva from the dev setup. we need to refactor cli arg handling down the road to get rid of this error as it is caused by assuming that the first cli arg represents the file to open. this is only true in some cases.

Linked Issues

Fixes #[Issue]

[tilmx]

Fancy!