Deprecate the nu_scripts version of stdlib-candidate (#1042)

Deprecates the existing `stdlib-candidate` directories in `nu_scripts`
since `std-rfc` has now transitioned to the main repo. Updates readme
and renamed directories.

stdlib-candidate-archive/stdlib-candidate-older/tests/bulk-rename.nu

@@ -0,0 +1,98 @@
+use std assert
+use ../std-rfc 'bulk-rename'
+
+const fixture = [
+    .gitignore
+    Cargo.toml
+    LICENSE
+    README.md
+    src
+    test.nu
+]
+
+export def 'test ls' [] {
+    let expects = [
+        .gitignore # hidden by ls
+        _Cargo.toml
+        _LICENSE
+        _README.md
+        _src
+        _test.nu
+    ]
+    test $expects {
+        ls $in | bulk-rename { '_' + $in }
+    }
+}
+
+export def 'test --no-execute' [] {
+    test $fixture {
+        ls $in | bulk-rename --no-execute { '_' + $in }
+    }
+}
+
+export def 'test --verbose' [] {
+    let expects = [
+        # .gitignore unchanged
+        _Cargo.toml
+        _LICENSE
+        _README.md
+        _src
+        _test.nu
+    ]
+    let renamed = test $fixture {
+        # Note: Currently failing due to Nushell core #13267
+        # Remove the 'sort' once it is fixed
+        # ls $in | bulk-rename --verbose --no-execute { '_' + $in }
+        ls $in | bulk-rename --verbose --no-execute { '_' + $in } | sort
+    }
+    assert equal ($renamed.new | each { path basename }) $expects
+}
+
+export def 'test skip-extensions' [] {
+    let expects = [
+        .gitignore
+        Cargo.toml
+        LICENSE.txt # changed
+        README.md
+        src.txt # changed
+        test.nu
+    ]
+    test $expects {
+        ls $in | bulk-rename { |path|
+            if $path.input.name ends-with $path.stem {
+                $path.stem + .txt
+            }
+        }
+    }
+}
+
+export def 'test glob' [] {
+    let expects = [
+        LICENSE # skipped
+        _.gitignore
+        _Cargo.toml
+        _README.md
+        _test.nu
+        src # skipped
+    ]
+    test $expects {
+        glob ($in | path join *.*) | bulk-rename { '_' + $in }
+    }
+}
+
+def test [expects: list<string> command: closure] {
+    let test_dir = $nu.temp-path | path join (random uuid)
+    def actual-files [] {
+        ls --all --short-names $test_dir | get name | sort
+    }
+    # before
+    mkdir $test_dir
+    $fixture | each { |name| touch ($test_dir | path join $name) }
+    assert equal (actual-files) $fixture
+    # test
+    let renamed = $test_dir | do $command
+    assert equal (actual-files) $expects
+    # after
+    rm --recursive --force $test_dir
+    $renamed
+}