LibWeb: Add default padding around contents of text <input> elements

This patch adds a default padding around the contents of text <input>
elements. It adds these defaults to the existing style attribute in
'HTMLInputElement::create_shadow_tree_if_needed()'.

Use a default padding for text <input> elements:
- padding-top and padding-bottom: 1px
- padding-left and padding-right: 2px

These values seems to align with what other browsers do.

Userland/Libraries/LibWeb/HTML/HTMLInputElement.cpp

@@ -172,7 +172,7 @@ void HTMLInputElement::create_shadow_tree_if_needed()
     if (initial_value.is_null())
         initial_value = String::empty();
     auto element = document().create_element(HTML::TagNames::div);
-    element->set_attribute(HTML::AttributeNames::style, "white-space: pre");
+    element->set_attribute(HTML::AttributeNames::style, "white-space: pre; padding-top: 1px; padding-bottom: 1px; padding-left: 2px; padding-right: 2px");
     m_text_node = adopt_ref(*new DOM::Text(document(), initial_value));
     m_text_node->set_always_editable(true);
     m_text_node->set_owner_input_element({}, *this);