Positional shortcodes cannot be single quoted

[WayneAllen]

The following shortcode results in a single element in the $atts array: [test "some long text"]
array(0 => "some long text")

The following shortcode results in 3 elements in the $attrs array: [test 'some long text']
array(0 => "'some", 1 => "long", 2 => "text'")

[tyxla]

Related: #5914

This bug has been there since the introduction of positional shortcode attributes in [6911].

[tyxla]

Adding support for single quote characters for positional shortcode attributes. Adding unit tests for attributes wrapped with single quotes.

[miqrogroove]

This is not a bug.

[swissspidy]

Duplicate of #37304.