extension library draft

[jafu888]

This outlines the two extension libraries. Views and Compose.
The goal is to contain a collection of View and Compose stand alone components that may depend on ConstraintLayout
and we find helpful in developing Views or Compose Applications.

Compose as much as is possible should be pure kotlin multi-platform with intent to support multi-platform
Views should be as much as possible pure java/android to be as backward compatible as possible.
We will welcome contributions.

Everything is subject to change.
But this provides a concrete proposal for us to work against.
Several things are missing and need to be in place for release:

1. test/android
2. projects to run against
3. comments, documentation and examples
   1. Readme's in all directories contain files.
   2. Are methods all commented