Migrate OAuth store to Pinia

src/components/OAuth/List.vue

src/components/OAuth/Row.vue

src/store/index.js

src/store/oauth.js

src/stores/index.ts

src/stores/oauth.ts

src/views/Repos/Create.vue

tests/unit/store/auth.spec.js

tests/unit/store/index.spec.js

tests/unit/stores/oauth.spec.js