Dropdowns

<Bs::Button {{dropdown}}>Open dropdown</Bs::Button>
<Bs::Dropdown @align="right" as |dropdown|>
  <dropdown.header>Dropdown header</dropdown.header>
  <dropdown.item @label="Action" />
  <dropdown.divider />
  {{! @glint-ignore }}
  <dropdown.item @label="Another action" {{on "click" (fn (mut this.xyz))}} />
</Bs::Dropdown>

<Bs::Button {{dropdown autoClose=false}}>This one stays open</Bs::Button>
<Bs::Dropdown as |dropdown|>
  <dropdown.header>Dropdown header</dropdown.header>
  <dropdown.item @label="Action" />
  <dropdown.divider />
  {{! @glint-ignore }}
  <dropdown.item @label="Another action" {{on "click" (fn (mut this.xyz))}} />
</Bs::Dropdown>