chore!: use @icp-sdk/core in imports

[viviveevee]

Description

• Update imports in dfx generate output: index.js and index.d.ts now import @icp-sdk/core instead of @dfinity/.
• The vite plugin now deduplicates the new package

Fixes # (issue)

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration.

Checklist:

• The title of this PR complies with Conventional Commits.
• I have edited the CHANGELOG accordingly.
• I have made corresponding changes to the documentation.

[peterpeterparker]

LGTM. I quickly tested the resolution of the imports provided in the PR in my IDE, all were resolved. ✅

Cannot tell about the dedupe as I actually never used it but, I guess it's correct.