Improve settings and chat focus

[zeroliu]

This PR includes the following features and bug fixes:

• Features
  • Added a settings to hide suggested prompts

• Bug Fixes

  • Open chat command will now properly focus the chat.
    

  • Reopen chat window will inherit the previous chat control settings.
    

• Dev Ex Improvements

  • Added a settings value context. Chat components can use it directly to avoid props drilling.
  • Removed unused variables and imports.
  • Changed how chat focus is working. Made it more reliable and easier to work with.

[logancyang]

As discussed, this is the right direction for this project. We need to refactor to use context more everywhere.

Since the copilot-plus change is coming in, this one will come in after.

[leventov]

@logancyang you mean that you will release the new project structure as part of the "base" open source version, so you want to merge third-party PRs on top of that structure? What's your ETA for this release?

[logancyang]

@leventov Copilot plus alpha will be released today as v2.7.3 if nothing else happens.

[zeroliu]

@logancyang I rebased the latest master branch and fixed merge conflicts