Allow slot content in GlDisclosureDropdownItem without template#list-item

from: gitlab!130543 (merged)

Using <gl-disclosure-dropdown-item> requires <template #list-item> to ensure that correct padding is applied to item. It's not obvious to consumers that this causes styling issues when using:

<gl-disclosure-dropdown-item @action="...">
  ...
</gl-disclosure-dropdown-item>

That the correct usage is:

<gl-disclosure-dropdown-item @action="...">
  <template #list-item>
    ...
  </template>
</gl-disclosure-dropdown-item>

Proposal: explore alternatives to applying padding to list items to remove <template #list-item> being required, or allow for both direct slot and template usage.