Make default config more consistent (#13399)

<!--
if this PR closes one or more issues, you can automatically link the PR
with
them by using one of the [*linking
keywords*](https://docs.github.com/en/issues/tracking-your-work-with-issues/linking-a-pull-request-to-an-issue#linking-a-pull-request-to-an-issue-using-a-keyword),
e.g.
- this PR should close #xxxx
- fixes #xxxx

you can also mention related issues, PRs or discussions!
-->

# Description
<!--
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.
-->

Fixes some minor config inconsistencies:
- Add default value for `shape_glob_interpolation` to light theme, as it
is missing
- Add right padding space to `shape_garbage` options
- Use a integer value for `footer_mode` instead of a string
- Set `buffer_editor` to null instead of empty string

# User-Facing Changes
<!-- List of all changes that impact the user experience here. This
helps us keep track of breaking changes. -->
N/A

# 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` to
check that you're using the standard code style
- `cargo test --workspace` to check that all tests pass (on Windows make
sure to [enable developer
mode](https://learn.microsoft.com/en-us/windows/apps/get-started/developer-mode-features-and-debugging))
- `cargo run -- -c "use toolkit.nu; toolkit test stdlib"` to run the
tests for the standard library

> **Note**
> from `nushell` you can also use the `toolkit` as follows
> ```bash
> use toolkit.nu # or use an `env_change` hook to activate it
automatically
> toolkit check pr
> ```
-->
N/A
# 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.
-->
N/A

crates/nu-utils/src/sample_config/default_config.nu

@@ -47,7 +47,7 @@ let dark_theme = {
     shape_flag: blue_bold
     shape_float: purple_bold
     # shapes are used to change the cli syntax highlighting
-    shape_garbage: { fg: white bg: red attr: b}
+    shape_garbage: { fg: white bg: red attr: b }
     shape_glob_interpolation: cyan_bold
     shape_globpattern: cyan_bold
     shape_int: purple_bold
@@ -114,7 +114,8 @@ let light_theme = {
     shape_flag: blue_bold
     shape_float: purple_bold
     # shapes are used to change the cli syntax highlighting
-    shape_garbage: { fg: white bg: red attr: b}
+    shape_garbage: { fg: white bg: red attr: b }
+    shape_glob_interpolation: cyan_bold
     shape_globpattern: cyan_bold
     shape_int: purple_bold
     shape_internalcall: cyan_bold
@@ -226,9 +227,9 @@ $env.config = {
 
     color_config: $dark_theme # if you want a more interesting theme, you can replace the empty record with `$dark_theme`, `$light_theme` or another custom record
     use_grid_icons: true
-    footer_mode: "25" # always, never, number_of_rows, auto
+    footer_mode: 25 # always, never, number_of_rows, auto
     float_precision: 2 # the precision for displaying floats in tables
-    buffer_editor: "" # command that will be used to edit the current line buffer with ctrl+o, if unset fallback to $env.EDITOR and $env.VISUAL
+    buffer_editor: null # command that will be used to edit the current line buffer with ctrl+o, if unset fallback to $env.EDITOR and $env.VISUAL
     use_ansi_coloring: true
     bracketed_paste: true # enable bracketed paste, currently useless on windows
     edit_mode: emacs # emacs, vi