[OpenJS Ops] Change "Collab Space" to "Working Group"

[kj-powell]

The CPC has decided to change the term "collab space" to "working group" across the Foundation. I've gone through all things OpenJS and compiled a list of things that need to be updated so we can keep track.

• Security collab space
• OpenVis collab space
• Standards collab space
• pkg-vuln-collab-space
• Package metadata interoperability collab space
• GH home page
• CPC page
• CPC collab spaces
• Sustainability collab space
• Website security page
• Website collaboration page
• CPC charter
• YouTube
• PCC Meetings

I will also post issues in the current collab spaces so they can make the changes in their own repos. For the rest, it would be great if we could have some volunteers to make the changes on GitHub. OpenJS staff can take care of the website and YouTube.

Thanks!