Refactor InnerBrowser class

[ghost]

General refactor to file InnerBrowser.php.

This PR...

• [x] makes it easier to navigate through the class.
• [x] reduces the file size from 2065 lines to 1626.
• [x] does not make logic changes.
• [x] creates individual traits responsible for the implementation of each interface used in the class.
• [x] respect the order of implementation of the methods.
• [x] organizes the methods: private first, protected second and public last.
• [x] alphabetize methods.
• [x] uses ʻuse` statements if possible.
• [x] adds BrowserInterface to see clearly (without docblocks or code implementation) which public methods this class provides.