* Remove panic from BlockCommands run function
Instead of panicing, the run method now returns an error to prevent
nushell from unexpected termination.
* Add ability to open command to run with blocks
The open command tries to parse the content of the file
if there is a command called 'from (file ending)'. This works
fine if the command was 'built in' because the run method doesn't
fail in this case. It did fail on a BlockCommand, though.
This change will first probe if the command contains a block and
evaluate it, if this is the case. If there is no block, it will run
the command the same way as before.
* Add test open files with BlockCommands
* Update open.rs
* Adjust file type on open with BlockCommand parser
Co-authored-by: JT <547158+jntrnr@users.noreply.github.com>
