[Cherry Pick] Use one NavHost (with a single navigation scaffold) (#102)

[ashnohe]

• Deduplicate lifecycle runtime compose

• kotlin 2.0 and compose gradle plugin

• update test & other versions

• Call navigate instead of recomposing HavHost

Previously, the app had a NavHost but didn't actually call navigate. NavHost's startDestination was read from external state (the currently selected nav item), which led to some undesirable behaviors.

• NavHost itself was recomposed when selecting a nav item.
• Pressing back always exited the app because you were always at the start destination.

Now the NavHost has a stable startDestination, and nav item state is driven by the NavHostController's current destination. Selecting a nav item calls navigate, and the user always goes back through the startDestination before exiting the app.

• Use type-safe navigation

• Make a package for navigation routes

• Migrate to type safe routes for main navhost

• Push Scaffold down to each top-level destination

• Extract nav suite scaffold to another composable

• Move ChatList, move and rename HomeViewModel

• Move Settings to its own package

• Remove Home and put its destinations in Main NavHost

• Remove Home composable and rename file

• Add NavigationSuiteScaffold around NavHost

• Change navigation layout type based on current destination

[mlykotom]

I changed 2 LoC -- moved a viewmodel retrieval to the composable parameter.