feat: warn developers for duplicated store keys#1731

rmartins90 wants to merge 2 commits intovuejs:v2vuejs/pinia:v2from

rmartins90:chore/1394-warn-if-two-stores-are-defined-with-the-same-namermartins90/pinia:chore/1394-warn-if-two-stores-are-defined-with-the-same-nameCopy head branch name to clipboard