Issue #3628021: Replace deprecated selectCollection() and selectDatabase()

Jerome TAMARELLErequested to merge
issue/mongodb-3628021:3628021-replace-deprecated-selectcollection into 8.x-2.x

selectCollection() and selectDatabase() are deprecated in mongodb/mongodb. This replaces every call site with getCollection() and getDatabase(), which are available in all supported versions of the library (^2.4 || ^1.21).

No behaviour change: the new methods are direct equivalents of the deprecated ones.

Merge request reports