Minor improvements in offcanvas-cart, cart and checkout

[crftwrk]

• Removed mini-cart footer text. Individual note can be simply added by hook:

/**
 * Offcanvas cart footer note
 */
add_action( 'woocommerce_widget_shopping_cart_before_buttons', 'bootscore_cart_footer_note' );

// Function for `woocommerce_widget_shopping_cart_before_buttons` action-hook.
function bootscore_cart_footer_note(){

  echo '<p class="small text-body-secondary">Some text</p>';

}