react-console: Consume v6 alphas and build Penta demo

[nicolethoen]

This will be especially powerful once the v6 Classic theme is done, so that the following deprecated components can exist alongside themed/non-deprecated components without any style clashing:

• Dropdown-deprecated (Dropdown-deprecate,DropdownItem-deprecated,DropdownToggle-deprecated)
• Select-deprecated (Select-deprecated,SelectOptionObject-deprecated,SelectVariant-deprecated)

Once the official alpha is announced, it should be pulled in to user feedback's v6 branch.

Once feedback is given regarding how the deprecated components behaved throughout the migration, an issue should be opened as a follow up (and addressed ASAP) to remove usage of deprecated components.

The v6 branch should also be updated to include all changes made to the main branch since the v6 branch was created.

Once the code merges and a v6-alpha of this extension is available, it should be pulled into the v6 branch on org.