Allow configuring base FQCN used in getFullyQualifiedClassName()

[slaFFik]

Right now WPForms is hardcoded:

wpforms-phpcs/WPForms/Sniffs/BaseSniff.php

Lines 221 to 223 in 67dde27

	// Fix WPForms.
	// Remove _plugin for main plugin class, which is usually Plugin.
	$fqcn = str_replace( [ 'wp_forms', '_plugin' ], [ 'wpforms', '' ], $fqcn );

But in other products (like WPAuth) I will need to do the same thing - and currently, there is no way to configure that.