Move CLI related commands to nu-cli (#8832)

# Description

Part of the larger cratification effort.

Moves all `reedline` or shell line editor specific commands to `nu-cli`.

## From `nu-cmd-lang`:
- `commandline`
- This shouldn't have moved there. Doesn't directly depend on reedline
but assumes parts in the engine state that are specific to the use of
reedline or a REPL

## From `nu-command`:
- `keybindings` and subcommands
  - `keybindings default`
  - `keybindings list`
  - `keybindings listen`
    - very `reedline` specific
- `history`
  - needs `reedline`
- `history session`

## internal use
Instead of having a separate `create_default_context()` that calls
`nu-command`'s `create_default_context()`, I added a `add_cli_context()`
that updates an `EngineState`


# User-Facing Changes

None

## Build time comparison

`cargo build --timings` from a `cargo clean --profile dev`

### total
main: 64 secs
this: 59 secs

### `nu-command` build time

branch | total| codegen | fraction  
---|---|---|---
main | 14.0s | 6.2s | (44%)
this | 12.5s | 5.5s | (44%)

`nu-cli` depends on `nu-command` at the moment.
Thus it is built during the code-gen phase of `nu-command` (on 16
virtual cores)

# Tests + Formatting

I removed the `test_example()` facilities for now as we had not run any
of the commands in an `Example` test and importing the right context for
those tests seemed more of a hassle than the duplicated
`test_examples()` implementations in `nu-cmd-lang` and `nu-command`

crates/nu-cli/src/commands/mod.rs

@@ -0,0 +1,18 @@
+mod commandline;
+mod default_context;
+mod history;
+mod history_session;
+mod keybindings;
+mod keybindings_default;
+mod keybindings_list;
+mod keybindings_listen;
+
+pub use commandline::Commandline;
+pub use history::History;
+pub use history_session::HistorySession;
+pub use keybindings::Keybindings;
+pub use keybindings_default::KeybindingsDefault;
+pub use keybindings_list::KeybindingsList;
+pub use keybindings_listen::KeybindingsListen;
+
+pub use default_context::add_cli_context;