Speed up terminal reconnection

[Tyriar]

• Merge Improve pty host startup marks/traces, revive terminal procs in parallel #186041 which this builds upon

Summary:

• Terminals are all re-created synchronously, this speeds up reconnection a little, but the biggest win here is the user should see all the restored terminals appear all at once instead of trickling in
• Added replay terminal stats
• Remove orphan check when attaching to processes (> 50% speed of replay)
  • Before (10 terminals): willReplay -> didReplay
    • Run 1: 7504ms
    • Run 2: 7495ms
  • After (10 terminals): willReplay -> didReplay
    • Run 1: 3433ms
    • Run 2: 3545ms
• The removal of the orphan check may fix Reattached to the wrong terminal #133542, I want to verify more before closing that though

Fixes #186068
Fixes #186069
Part of #185393
Part of #133542