[repoapi] move get_repository function into a new repoapi module This new module aims to host the function of the new API replacing the old DBAPI. `get_repository` is still needed hence moved to the new module. Related to #2503918

addressbook
basket
blog
book
calendar
comment
company
email
file
folder
i18ncontent
keyword
link
mailinglist
person
tag
timeseries
vcsfile