Feature Request: Menu Icon Filter

Hello and thank you for this great plugin.

I was looking into how to change the admin menu icon for wpcf7 object page and noticed that there isn’t a filter in place.

Any change we could change line 8 of admin/admin.php from this:

add_object_page( __( 'Contact Form 7', 'contact-form-7' ),
	__( 'Contact', 'contact-form-7' ),
	'wpcf7_read_contact_forms', 'wpcf7',
	'wpcf7_admin_management_page' );

to this?:

add_object_page( __( 'Contact Form 7', 'contact-form-7' ),
	__( 'Contact', 'contact-form-7' ),
	'wpcf7_read_contact_forms', 'wpcf7',
	'wpcf7_admin_management_page',
        apply_filters('wpcf7_admin_menu_icon','') );

Leaving the filter empty would still show the default icon as it is at the moment, but it would give theme authors a way to change it to something like: dashicons-email-alt

Thanks again,
Marc

https://ww.wp.xz.cn/plugins/contact-form-7/