Implement base class & file structure.

Within this sub-task we want the base structure of the new Moodle 4.0 navigation to be implemented.

Acceptance criteria

• Using the example structure within this issue, create the required sub directories & files
• Using the example within this issue, implement the base functions within the secondary navigation class
• Implement new magic method for Secondary navigation
  • $PAGE->secondarynavigationview calls the function magic_get_secondarynavview within lib/pagelib. This would create a new secondary_navigation_view and triggers the initialise function within secondary_navigation_view.

Example structure:

/lib/classes
            /navigation
                       /views
                             /secondary.php

Example class stub:

class secondary_navigation_view extends navigation_node {
    // Sets up the view with basic settings and preparse it for use.
    public function __construct(array $properties) {}
    // Initialise the view based navigation based on the current context.
    public function initialise() {}
    /This function recursively scans nodes until it finds the active node or there are no more nodes.
    etc.....
}