feat: Add access to the URL and headers from plugin

[jaybz]

I've taken the liberty of adding a few plugin methods that would allow access to the URL and headers of requests and responses. This also allows setting headers for requests via plugins but responses are read-only. This PR adds the following methods:

Request methods:

• context.request.getHeader('<HEADER_NAME>')
• context.request.setHeader('<HEADER_NAME>', '<HEADER_VALUE>')
• context.request.getHeaders()
• context.request.setHeaders(<HEADER_ARRAY>)
• context.request.getURL()

Response methods:

• context.response.getHeader('<HEADER_NAME>')
• context.response.getHeaders()
• context.response.getURL()

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[flawiddsouza]

Hi @jaybz, this is a really nice PR. Appreciate it.

Subtitution of environment variables doesn't make sense for response headers.

Other than that, everything looks good.

[jaybz]

@flawiddsouza Looks like the test is failing due to a missing tag. Unfortunately I don't think there's a way to include tags in pull requests and I'm not sure how you'd want to proceed at this point.

edit: Hmm, seems like your comment didn't load before I posted this one. Let me fix that and update the PR.

[flawiddsouza]

@flawiddsouza Looks like the test is failing due to a missing tag. Unfortunately I don't think there's a way to include tags in pull requests and I'm not sure how you'd want to proceed at this point.

I've pushed a fix for this. Please bring this branch up to date with the latest main. Tests should pass after that.

[flawiddsouza]

Ignore the test for now. I'll fix it later. Thanks for the PR 🎉