Move new/recent column from Welcome to Explorer view

[digitarald]

📯 This is an early idea and we'd love to hear your thoughts, ideas and concerns to further explore it.

Context

• The Explorer is the natural UI surface of files and folders.
• Explorer already duplicates items that are also offered on the Welcome page, like opening a folder, checking out a repo, or creating a new file.
• Explorer also offers extension contributions that are already used by Java to add their project wizard.
• If empty, the Explorer has a lot of unused vertical space.

Proposed solution

Move the new and recent shortcuts from the left side of the Welcome page to the Explorer.

Also revisit current content for the welcome.

Open questions

• Should this also open Explorer by default for new windows to make sure the options are visible?

[digitarald]

Circulated this with a few people and got little excitement.

Given that VS Code starts with Explorer closed, this requires a bit more impact. If we have additional content for the Get Started page and need the space, we can revisit.