BSON Vector support, easily create ObjectId instances, usability improvements

### BSON

- Added support for vector types: `Vector`, `ByteVector`, `FloatVector` and `BooleanVector` (#106, !194)

### Drivers (official)

- Added the method `MongoCollection.newId()` to easily generate new `ObjectId` instances using the collection's generator (!203)
- Fixed a dependency declaration issue which lead to `JvmBsonContext` not being available to users (!207)

### DSL

- Fixed `gteNotNull` and similar operators breaking when the optional filter is not present (!204)
- Nullable numbers are now allowed in aggregation accumulators (!205)