SpEL support for Document collation

[blueiceprj]

Hi,

It would be very useful if @document annotions has dynamic value support according to spring parameters.

Like that

@Document(collection = "XYZ", collation = "${spring.data.mongodb.collation}")

Thanks.

[christophstrobl]

Thanks for creating the issue.
Resolving property placeholders depends on: spring-projects/spring-data-commons#2369