Hot take: we set the tab title for cmd and powershell by default

[zadjii-msft]

I'm submitting this PR to start a discussion about this. If we reach consensus against it, I'm happy to close it. I'm also liking Plan B the more I think on it.

Summary of the Pull Request

We don't set it for WSL, Azure, or Powershell core

Plan B: Add an "initialTabTitle" setting. With that set, we'll ignore the first title conpty sets for us. If conpty sets another title, we'll blow the initial title away and continue using the title from VT. This would be more similar to how cmd and powershell use the title from a shortcut currently.

References

literally every issue that mentions the length of the tab title, but #2327 was the one that broke the camel's back.

PR Checklist

• Closes #the-endless-stream-of-complaints-about-tab-titles
• CLA signed. If not, go over here and sign the CLA
• Tests added/passed
• Requires documentation to be updated - Probably does
• I have not discussed this with core contributors already.

[mcpiroman]

Maybe instead of initialTabTitle being string make overridableTabTitle boolean, that when set true would make the existing tabTitle behave as described in plan B. And true'd be actually the reasonable default.

[zadjii-msft]

Closed in favor of #2373