feat(api/v2): ⭐ Implement members routes

**[1] Feature Description**
get /members \
post /members \
get /members/[userId] \
del /members/[userId] \
put /members/[userId] \

get /members/[userId]/permissions \
put /members/[userId]/permissions -> also needs to support adding new ones (upsert) \
del /members/[userId]/permissions/[permId]