Remove undefined HTTP headers from TRPCClient

[jlalmes]

Closes: #1712

Remove undefined HTTP headers from TRPCClient

Added a transform to delete headers with undefined values before HTTP requests are sent by the TRPCClient.

{ "x-defined": "xyz", "x-undefined": undefined } 
// is transformed to
{ "x-defined": "xyz" }

Changes

• Added headers transformer to httpRequest method
• Removed undefined typing from HTTPHeaders record
• Added test case for removing undefined headers
• Updated @trpc/client imports to relative path in tests
   

[vercel]

This pull request is being automatically deployed with Vercel (learn more).
To see the status of your deployments, click below or on the icon next to each commit.

next-prisma-starter – ./examples/next-prisma-starter

🔍 Inspect: https://vercel.com/trpc/next-prisma-starter/EHRxiiLu4rgz3CMhHbkUAwS7XhRm
✅ Preview: https://next-prisma-starter-git-bugfix-issue-1712-trpc.vercel.app

www – ./www

🔍 Inspect: https://vercel.com/trpc/www/BaCQNWi7L37PRi3QNcqzU4kMsWa9
✅ Preview: https://www-git-bugfix-issue-1712-trpc.vercel.app

[github-actions]

This pull request has been locked because it had no new activity for 30 days. If you think, this PR is still necessary, create a new one with the same branch. Thank you.