Add initial support for bracketed paste mode

[skyline75489]

Summary of the Pull Request

This adds "bracketed paste mode" to the Windows Terminal.

References

Supersedes #7508

PR Checklist

• Closes bracketed paste in conhost #395
• CLA signed. If not, go over here and sign the CLA
• Tests added/passed
• Documentation updated. If checked, please file a pull request on our docs repo and link it here: #xxx
• Schema updated.
• I've discussed this with core contributors already. If not checked, I'm ready to accept this work might be rejected in favor of a different grand plan. Issue number where discussion took place: #xxx

Detailed Description of the Pull Request / Additional comments

Validation Steps Performed

[skyline75489]

Dustin mentioned his effort to bring "bracketed paste mode" into conhost (#7508 (comment)). I don't know enough about conhost or conpty so I limited my implementation to WT. This is an early implementation and will conflict with #8875 , so I marked this as a draft.

[skyline75489]

This is pretty straightforward. I'm wondering if this has any side effects that I don't know about. If the overall direction is correct, I'll polish the PR later the mark it as ready for review.

[oising]

I don't think this is as straightforward as one might think. Are you filtering out an explicit end sequence from the source sequence before pasting? This is a common bypass attempted in malicious scenarios (update: just checked - you're not)

Here are some eye opening dirty tricks to digest if you haven't seen them before: https://thejh.net/misc/website-terminal-copy-paste

[skyline75489]

@oising that’s #8875. I made two separate PRs to minimize the diff

[zadjii-msft]

I don't see what's wrong with this. Thanks!

[zadjii-msft]

@msftbot make sure @DHowett signs off on this

[ghost]

Hello @zadjii-msft!

Because you've given me some instructions on how to help merge this pull request, I'll be modifying my merge approach. Here's how I understand your requirements for merging this pull request:

• I'll only merge this pull request if it's approved by @DHowett

If this doesn't seem right to you, you can tell me to cancel these instructions and use the auto-merge policy that has been configured for this repository. Try telling me "forget everything I just told you".

[oising]

@oising that’s #8875. I made two separate PRs to minimize the diff

Ah, apologies -- I missed that. Nice work :)

[skyline75489]

Closed in favor of #9034