add_render_attribute should treat boolean values as boolean attributes

[75th]

Prerequisites

• I have searched for similar features requests in both open and closed tickets and cannot find a duplicate.
• The feature is still missing in the latest stable version of Elementor ( Elementor Pro )

What problem is your feature request going to solve? Please describe.

If you provide an a value of boolean false to an attribute in Controls_Stack::add_render_attribute, then get_render_attribute_string still prints that attribute name with no value. This is contrary to HTML's concept of a "boolean attribute", for which <img data-attribute /> has a true boolean attribute of data-attribute, and only <img /> has that attribute as false.

Describe the solution you'd like

These lines in the add_render_attribute function:

if ( empty( $this->render_attributes[ $element ][ $key ] ) ) {
	$this->render_attributes[ $element ][ $key ] = [];
}

...should be something more like this to properly handle a boolean false:

if ( empty( $this->render_attributes[ $element ][ $key ] ) && false !== $this->render_attributes[ $element ][ $key ] ) {
	$this->render_attributes[ $element ][ $key ] = [];
}

Describe alternatives you've considered

I know that solution could have side effects on existing code, so perhaps instead some magic constant could be used to specify the value, so at least we could do something like this:

$this->add_render_attribute(
	'element',
	[
		'class' => ['some-scroller'],
		'data-is-scroller' => $is_scroller ? true : ELEMENTOR_ACTUALLY_FALSE_ATTRIBUTE,
	]
);

instead of this dance, which is what is currently necessary:

$attributes = [ 'class' => [ 'some-scroller' ] ];

if($is_scroller) {
  $attributes['data-is-scroller'] = true;
}

$this->add_render_attribute('element', $attributes),

Additional context

No response