### Godot version

4.0.rc6.mono.official

### System information

macOS 12.0.1

### Issue description

Just a minor visual issue.

When opening an empty directory the focus highlight is drawn incorrectly. It looks like the UI is drawing a smaller rectangle within the main rect:
<img width="1058" alt="Bildschirmfoto 2023-02-28 um 14 13 31" src="https://user-images.githubusercontent.com/11627131/221868794-7450606d-e758-4104-8f33-182d9779d7f8.png">


This behavior also changes when you hover over other items in the view, so I'm not sure if this a general issue with the focus highlighting or just an issue in the directory view:
<img width="1052" alt="Bildschirmfoto 2023-02-28 um 14 32 54" src="https://user-images.githubusercontent.com/11627131/221869308-4756f26e-cda2-4057-be1e-7439030895dc.png">


### Steps to reproduce

1. New Project
2. Browse
3. Create Folder
4. Click or Tab to set focus on the empty directory view

### Minimal reproduction project

N/A
glBindBuffer(GL_ARRAY_BUFFER, new_buffers[0]);
		GLES3::Utilities::get_singleton()->buffer_allocate_data(GL_ARRAY_BUFFER, new_buffers[0], data.max_instance_buffer_size, nullptr, GL_STREAM_DRAW, "Batch UBO[0][0]");
		
		glBindBuffer(GL_UNIFORM_BUFFER, new_buffers[1]);
		GLES3::Utilities::get_singleton()->buffer_allocate_data(GL_UNIFORM_BUFFER, new_buffers[1], sizeof(LightUniform) * data.max_lights_per_render, nullptr, GL_STREAM_DRAW, "2D lights UBO[0]");
		
		glBindBuffer(GL_UNIFORM_BUFFER, new_buffers[2]);
		GLES3::Utilities::get_singleton()->buffer_allocate_data(GL_UNIFORM_BUFFER, new_buffers[2], sizeof(StateBuffer), nullptr, GL_STREAM_DRAW, "2D state UBO[0]");
		DataBuffer db;
		db.instance_buffers.push_back(new_buffers[0]);
		db.light_ubo = new_buffers[1];
		db.state_ubo = new_buffers[2];
		db.last_frame_used = 0;
		db.fence = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, 0);
		state.canvas_instance_data_buffers[i] = db;
	}
	glBindBuffer(GL_ARRAY_BUFFER, 0);
	glBindBuffer(GL_UNIFORM_BUFFER, 0);
	state.instance_data_array = memnew_arr(InstanceData, data.max_instances_per_buffer);
	state.light_uniforms = memnew_arr(LightUniform, data.max_lights_per_render);
	{
		const uint32_t indices[6] = { 0, 2, 1, 3, 2, 0 };
		glGenVertexArrays(1, &data.indexed_quad_array);
		glBindVertexArray(data.indexed_quad_array);
		glBindBuffer(GL_ARRAY_BUFFER, data.canvas_quad_vertices);
		glGenBuffers(1, &data.indexed_quad_buffer);
		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, data.indexed_quad_buffer);
		glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(uint32_t) * 6, indices, GL_STATIC_DRAW);
		glBindVertexArray(0);
	}