Migrate away from deprecated slots syntax
The following discussion from !993 (merged) should be addressed:
nitpick: Again, outside the current MR's scope
slotattribute has been deprecated since Vue 2.6, could we please create a follow-up issue to replace them with
v-slotdirective? Warning: this might affect unit tests as vue-test-utils still work with Vue 2.5 syntax and you will need to stub a component to test its slots.