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

How Has This Been Tested?

Covered by e2e

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.