Cratification: Break out nu_cmd_lang into a separate crate (#8181)

# Description

This breaks out the core_commands into a separate crate called
nu_cmd_lang

_(Thank you for improving Nushell. Please, check our [contributing
guide](../CONTRIBUTING.md) and talk to the core team before making major
changes.)_

_(Description of your pull request goes here. **Provide examples and/or
screenshots** if your changes affect the user experience.)_

# User-Facing Changes

_(List of all changes that impact the user experience here. This helps
us keep track of breaking changes.)_

# Tests + Formatting

Don't forget to add tests that cover your changes.

Make sure you've run and fixed any issues with these commands:

- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass

# After Submitting

If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.

crates/nu-command/src/default_context.rs

@@ -3,7 +3,7 @@ use nu_protocol::engine::{EngineState, StateWorkingSet};
 use crate::*;
 
 pub fn create_default_context() -> EngineState {
-    let mut engine_state = EngineState::new();
+    let mut engine_state = nu_cmd_lang::create_default_context();
 
     let delta = {
         let mut working_set = StateWorkingSet::new(&engine_state);
@@ -26,52 +26,6 @@ pub fn create_default_context() -> EngineState {
         #[cfg(feature = "sqlite")]
         add_database_decls(&mut working_set);
 
-        // Core
-        bind_command! {
-            Alias,
-            Break,
-            Commandline,
-            Const,
-            Continue,
-            Def,
-            DefEnv,
-            Describe,
-            Do,
-            Echo,
-            ErrorMake,
-            ExportAlias,
-            ExportCommand,
-            ExportDef,
-            ExportDefEnv,
-            ExportExtern,
-            ExportUse,
-            Extern,
-            For,
-            Help,
-            HelpAliases,
-            HelpCommands,
-            HelpModules,
-            HelpOperators,
-            Hide,
-            HideEnv,
-            If,
-            Ignore,
-            Overlay,
-            OverlayUse,
-            OverlayList,
-            OverlayNew,
-            OverlayHide,
-            Let,
-            Loop,
-            Module,
-            Mut,
-            Return,
-            Try,
-            Use,
-            Version,
-            While,
-        };
-
         // Charts
         bind_command! {
             Histogram
@@ -498,9 +452,6 @@ pub fn create_default_context() -> EngineState {
             MathEvalDeprecated,
         };
 
-        #[cfg(feature = "plugin")]
-        bind_command!(Register);
-
         working_set.render()
     };