Add initial canonical layout implementations

[alexvanyo]

Adds the initial implementations of canonical layouts using the current set of layout technologies.

There are 8 in total:

• List-Detail
  • with activity embedding
  • with Compose (TwoPane)
  • with views (SlidingPaneLayout)
• Feed
  • with Compose (LazyVerticalGrid)
  • with views (RecyclerView)
• Supporting Panel
  • with Compose (TwoPane)
  • with fragments
  • with views

These samples are barebones, just to show the layout behavior and standalone examples of using each of these technologies to achieve implementations of the canonical layouts.

[alexvanyo]

Merging to be able to have public links to these, I'm going to create a follow-up PR with the README and @Gurupreet 's initial feedback!