Prevent improper files (like /dev/random) from being used as file arguments (#10733)

* Implement check before adding path to files

* fix problem where directories were removed from args.files

* Revert "Implement check before adding path to files"

This reverts commit c123944d9b.

* Dissallow opening of irregular non-symlink files

* Fixed issue with creating new file from command line

* Fixed linting error.

* Optimized regularity check as suggested in review

* Created DocumentOpenError Sum Type to switch on in Application

* Forgot cargo fmt

* Update helix-term/src/application.rs

Accept suggestion in review.

Co-authored-by: Michael Davis <mcarsondavis@gmail.com>

* Moved thiserror version configuration to the workspace instead of the individual packages.

---------

Co-authored-by: Michael Davis <mcarsondavis@gmail.com>

helix-term/src/commands.rs

@@ -69,6 +69,7 @@ use crate::job::{self, Jobs};
 use std::{
     cmp::Ordering,
     collections::{HashMap, HashSet},
+    error::Error,
     fmt,
     future::Future,
     io::Read,