nu-cli refactor moving commands into their own crate nu-command (#2910)

* move commands, futures.rs, script.rs, utils

* move over maybe_print_errors

* add nu_command crate references to nu_cli

* in commands.rs open up to pub mod from pub(crate)

* nu-cli, nu-command, and nu tests are now passing

* cargo fmt

* clean up nu-cli/src/prelude.rs

* code cleanup

* for some reason lex.rs was not formatted, may be causing my error

* remove mod completion from lib.rs which was not being used along with quickcheck macros

* add in allow unused imports

* comment out one failing external test; comment out one failing internal test

* revert commenting out failing tests; something else might be going on; someone with a windows machine should check and see what is going on with these failing windows tests

* Update Cargo.toml

Extend the optional features to nu-command

Co-authored-by: Jonathan Turner <jonathandturner@users.noreply.github.com>

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

@@ -0,0 +1,109 @@
+use nu_test_support::fs::Stub::FileWithContentToBeTrimmed;
+use nu_test_support::playground::Playground;
+use nu_test_support::{nu, pipeline};
+
+#[test]
+fn summarizes_by_column_given() {
+    Playground::setup("histogram_test_1", |dirs, sandbox| {
+        sandbox.with_files(vec![FileWithContentToBeTrimmed(
+            "los_tres_caballeros.csv",
+            r#"
+                first_name,last_name,rusty_at
+                Andrés,Robalino,Ecuador
+                Jonathan,Turner,Estados Unidos
+                Yehuda,Katz,Estados Unidos
+            "#,
+        )]);
+
+        let actual = nu!(
+            cwd: dirs.test(), pipeline(
+            r#"
+                open los_tres_caballeros.csv
+                | histogram rusty_at countries
+                | where rusty_at == "Ecuador"
+                | get countries
+            "#
+        ));
+
+        assert_eq!(
+            actual.out,
+            "**************************************************"
+        );
+        // 50%
+    })
+}
+
+#[test]
+fn summarizes_by_values() {
+    Playground::setup("histogram_test_2", |dirs, sandbox| {
+        sandbox.with_files(vec![FileWithContentToBeTrimmed(
+            "los_tres_caballeros.csv",
+            r#"
+                first_name,last_name,rusty_at
+                Andrés,Robalino,Ecuador
+                Jonathan,Turner,Estados Unidos
+                Yehuda,Katz,Estados Unidos
+            "#,
+        )]);
+
+        let actual = nu!(
+            cwd: dirs.test(), pipeline(
+            r#"
+                open los_tres_caballeros.csv
+                | get rusty_at
+                | histogram
+                | where value == "Estados Unidos"
+                | get count
+            "#
+        ));
+
+        assert_eq!(actual.out, "2");
+    })
+}
+
+#[test]
+fn help() {
+    Playground::setup("histogram_test_3", |dirs, _sandbox| {
+        let help_command = nu!(
+        cwd: dirs.test(), pipeline(
+        r#"
+                help histogram
+            "#
+        ));
+
+        let help_short = nu!(
+        cwd: dirs.test(), pipeline(
+        r#"
+                histogram -h
+            "#
+        ));
+
+        let help_long = nu!(
+        cwd: dirs.test(), pipeline(
+        r#"
+                histogram --help
+            "#
+        ));
+
+        assert_eq!(help_short.out, help_command.out);
+        assert_eq!(help_long.out, help_command.out);
+    })
+}
+
+#[test]
+fn count() {
+    let actual = nu!(
+        cwd: ".", pipeline(
+        r#"
+            echo [[bit];  [1] [0] [0] [0] [0] [0] [0] [1]]
+            | histogram bit
+            | sort-by count
+            | reject frequency
+            | to json
+        "#
+    ));
+
+    let bit_json = r#"[{"bit":"1","count":2,"percentage":"33.33%"},{"bit":"0","count":6,"percentage":"100.00%"}]"#;
+
+    assert_eq!(actual.out, bit_json);
+}