Make it more obvious how to start the kernel

[jtaylorchang]

Some options to consider:

• the kernel selector could have a button to open the kernel tab
• the kernel panel could be removed and instead merge with the kernel selector
  • Move logs to a modal opened from the kernel selector
  • Add connection UI to the kernel selector
  • Do not need kernel status because it is indicated already on the dropdown item
• the kernel panel could be merged with the project panel
• trying to run a Python cell without a kernel could display a tooltip