No entry to set "max-line-length" key for formatting in Godot addon settings... And question about .editorconfig

There is a "Lint Line Length" in addon settings menu which only affects linting. I read plugin.gd and found it was implemented by run the formatter executable with `--max-line-length=` flag:

```gdscript
func lint_code(script: GDScript) -> Array:
# ...
var formatter_arguments: Array = ["lint", ProjectSettings.globalize_path(script_path)]

var max_line_length := get_editor_setting(SETTING_LINT_LINE_LENGTH) as int
formatter_arguments.append("--max-line-length")
formatter_arguments.append(str(max_line_length))
# ...
var exit_code := OS.execute(get_editor_setting(SETTING_FORMATTER_PATH), formatter_arguments, output)
# ...
```

However for `format_code` function there is no line to add `--max-line-length` flag. This flag is valid for the executable itself for formatting, and line length is always a important attribute for a formatter, so it's weird the addon settings doesn't have any entry to set it, and it's quite easy to implement it by adding same codes to the `format code` function. I did so to let Lint Line Length value also affects formatting, and it works fine for me.

Besides `.editorconfig` file seems not work with addon. I tried formatting gdscript files with formatter executable directly using command lines in terminal, and it can find and use parameters in editor config file in parent directory correctly. So it's also weird that it doesn't work with addon. According to plugin.gd:

```gdscript
func get_editorconfig_format_on_save(script_path: String) -> Variant:
var editorconfig_path := ProjectSettings.globalize_path("res://.editorconfig")
# ...
```

Seems that it will only try to find editor config file in project root, and it only reads `gdscript_formatter_format_on_save` parameter from that file, ignoring other parameters. Is it intended?

EDIT:

Just quickly inspected `plugin.gd` again. Found why it ignores the `.editorconfig`. When you use the addon in godot editor, it creates a temp file in elsewhere:

```gdscript
var path_temporary_file := OS.get_temp_dir().path_join(
"gdscript_formatter_%d.gd" % Time.get_ticks_msec()
)
```

The addon will first formats the temp file, then replaces the actual file with it. For my system it creates the temp file in somewhere like `c:/temp/`, far away from my project directory. When use the executable to format it, it will only search through the temp file folder and temp file's parent folders for `.editorconfig`. That's why it can't find my project's `.editorconfig`.

So one of the simplest solutions is just create the temp file in the same folder with the original file you want to format, and it's also easy to implement. Since I'm busy now I may try this method when I have some free time.

Start in plugin.gd, comparing format_code with lint_code and inspecting get_editorconfig_format_on_save plus the temporary-file path. Verify that formatting receives the configured line length and that .editorconfig discovery works for project files. Done means both settings behave correctly when formatting through the Godot addon.

Written by the indexing model from the issue text.