feat(hmr): extend `acceptHMRUpdate` to allow for cleaning up side effects of existing store#2793

Anoesj wants to merge 1 commit intovuejs:v2vuejs/pinia:v2from

Anoesj:feat/hmr-clean-up-side-effectsAnoesj/pinia:feat/hmr-clean-up-side-effectsCopy head branch name to clipboard