feat(ui5-search-item): byline item support

[MapTo0]

• property: description to display byline text
• slot: image to display avatar in the item

<ui5-search-item text="List Item" description="Byline"></ui5-search-item>

<ui5-search-item text="List item" description="Byline">
  <ui5-avatar slot="image" size="XS">
    <img src="./img/John_Miller.png" alt="John Miller">
  </ui5-avatar>
</ui5-search-item>

<ui5-search-item text="List item" description="Byline" icon="globe"></ui5-search-item>

[elenastoyanovaa]

Add a sample in the playground

[elenastoyanovaa]

add docu that if an icon is set, the image will not be rendered

[elenastoyanovaa]

why not description? isn't it confusing to have a text property and render it as a .ui5-search-item-heading and a description and name it .ui5-search-item-subheading. Both of them are not heading semantically, why naming them like that.

[elenastoyanovaa]

Perhaps add a separate test sample pointing that it shows byline items, instead of polluting the old one's, it will be easier for testing and testers.