Fix: dst error on cp command (#7895)

Fixes #7693 

On `cp` commands there were two error which pass error message with
invalid detail about source and destination files . there error were for
Not exist file and Permission denied .

Examples:
  Before :
Copy `source_file_valid` to `destination_invalid_dir` throw this error ;
`copy file "/source_file_valid" failed: No such file or directory (os
error 2) `

 After this PR it will throw this if destination will be invalid :
`copying to destination "/destination_invalid_dir" failed: No such file
or directory (os error 2) `

it was for Permission denied too .

---------

Co-authored-by: Stefan Holderbach <sholderbach@users.noreply.github.com>

crates/nu-command/tests/commands/cp.rs

@@ -1,5 +1,8 @@
 use nu_test_support::fs::file_contents;
-use nu_test_support::fs::{files_exist_at, AbsoluteFile, Stub::EmptyFile};
+use nu_test_support::fs::{
+    files_exist_at, AbsoluteFile,
+    Stub::{EmptyFile, FileWithPermission},
+};
 use nu_test_support::nu;
 use nu_test_support::playground::Playground;
 use std::path::Path;
@@ -344,3 +347,37 @@ fn copy_ignores_ansi() {
         assert_eq!(actual.out, "success.txt");
     });
 }
+
+#[test]
+fn copy_file_not_exists_dst() {
+    Playground::setup("cp_test_17", |_dirs, sandbox| {
+        sandbox.with_files(vec![EmptyFile("valid.txt")]);
+
+        let actual = nu!(
+            cwd: sandbox.cwd(),
+            "cp valid.txt ~/invalid_dir/invalid_dir1"
+        );
+        assert!(
+            actual.err.contains("invalid_dir1") && actual.err.contains("copying to destination")
+        );
+    });
+}
+
+#[test]
+fn copy_file_with_read_permission() {
+    Playground::setup("cp_test_18", |_dirs, sandbox| {
+        sandbox.with_files(vec![
+            EmptyFile("valid.txt"),
+            FileWithPermission("invalid_prem.txt", false),
+        ]);
+
+        let actual = nu!(
+            cwd: sandbox.cwd(),
+            "cp valid.txt invalid_prem.txt",
+        );
+        assert!(
+            actual.err.contains("invalid_prem.txt")
+                && actual.err.contains("copying to destination")
+        );
+    });
+}