Edit: Fix missing context for instruction-based inputs

[umpox]

Description

@philipp-spiess noticed that Edit was not including context, which it should have been doing.

Recent work around commands + context improvements introduced a couple of bugs that weren't obvious:

• contextMessages are defaulted to [] from the Edit input, we had a bad check for these
• range is an optional value for ContextItem, but we rely on it to generate unique IDs for content within a file. This adds an extra ID mechanism to uniquely hash the content of the item alongside the file URI (if available)

Test plan

1. Create an edit,
2. Check preceding code and following code are included as context

[philipp-spiess]

crypto will only work in node so this will likely not compile in the web config. Maybe use the crypto-js package we already bundle?

cody/vscode/src/completions/providers/fireworks.ts

Line 548 in a7cf272

const gatewayTokenBytes = SHA256(SHA256(accessTokenBytes)).toString()

[umpox]

Thanks!

[sqs]

It would be great to have a test for this. The code around this is pretty tricky. I have a PR #3307 that is cleaning up related unused code. I'll see if I can add a test.