Fix to enable data- attributes to be parsed correctly

[titantwentyone]

Description

Currently the following results in two attributes being output on the target element. One being incorrect:

TextInput('something')
   ->extraAttributes(['data-foo' => 'bar']);

//Results in...
<div...
   datafoo='bar'
   data-foo='bar'
>

PR includes tests for basic html attributes, alpine attributes and data attributes.

• Visual changes (if any) are shown using screenshots/recordings of before and after.

Before PR:

After PR:

• composer cs command has been run.
• Changes have been tested.
• Documentation is up-to-date.

[danharrin]

Thanks