chore(assets): remove dead icon assets and consolidate icons/

Delete zero-referenced leftovers (31 img SVGs, duplicate top-level
vip badges, favicon/icon/person_background pngs, assets/fonts/,
tmp-debug/, gutenberg-extend.js and the FA eot/ttf/svg font formats)
and give icon-purpose SVGs one home in assets/icons/ (upload-add,
default favicon/logo, playing, user-certification) with every reference
updated. Icon SVG files were audited by name across PHP/CSS/JS before
deletion.

inc/helpers/comments/form-parts.php

@@ -85,7 +85,7 @@ if (!function_exists('aksrt_get_input_expand_but')) :
 					$dropdown .= '</div></div>';
 
 					if ($upload) {
-						$placeholder = get_template_directory_uri() . '/assets/img/upload-add.svg';
+						$placeholder = get_template_directory_uri() . '/assets/icons/upload-add.svg';
 						$dropdown .= '<div class="tab-pane fade dropdown-image" id="image-tab-' . esc_attr($upload_id) . '-2">';
 						$dropdown .= '<p><a class="muted-color input-image-address-tab" data-image-tab="#image-tab-' . esc_attr($upload_id) . '-1" href="javascript:;"><i class="fa fa-angle-left mr6" aria-hidden="true"></i>' . esc_html__('填写图片地址', 'aksrt') . '</a></p>';
 						$dropdown .= '<div class="form-upload comment-image-upload">';