For mozilla-mobile/fenix#8765: Add site item widget

[NotWoods]

WidgetSiteItemView is used to show a website inside bookmarks, history, collections, and other lists. Has the following API:

• iconView getter to load favicons into the view
• setText(label, caption) to set the text shown. If caption is null, the caption text view is hidden and the label is centered.
• addIconOverlay inserts other views above the iconView, such as a checkmark.
• setSecondaryButton(icon, contentDescription, onClickListener) will show an icon button with the given icon and content description. onClickListener is called when the button is clicked.
• removeSecondaryButton hides the button if it was previously shown by setSecondaryButton.

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Pull Request checklist

• Quality: This PR builds and passes detekt/ktlint checks (A pre-push hook is recommended)
• Tests: This PR includes thorough tests or an explanation of why it does not
• Changelog: This PR includes a changelog entry or does not need one
• Accessibility: The code in this PR follows accessibility best practices or does not include any user facing features

After merge

• Milestone: Make sure issues closed by this pull request are added to the milestone of the version currently in development.
• Breaking Changes: If this is a breaking change, please push a draft PR on Reference Browser to address the breaking issues.

[NotWoods]

bors r=gabrielluong

[bors]

Build succeeded:

• complete-push