Add Kotlin extension to accept Kotlin's Pair in `BulkOperations`

[2tsumo-hitori]

Related: #2313, f318185

Hello,

When using spring-data-mongodb with Kotlin, I encountered an inconvenience where the updateMulti API of the BulkOperations interface—as well as several other APIs—forces the use of Spring Framework’s utility Pair class. Consequently, Kotlin’s native Pair cannot be used directly, and developers are required to import or convert to Spring’s Pair, which is cumbersome.

To address this issue, I propose adding extension functions in the Kotlin module. These extension functions would accept Kotlin’s Pair as an argument, convert it internally to Spring’s Pair, and then delegate to the existing API.

I would appreciate any feedback on this proposal.

Thank you.

[mp911de]

Good idea. We'd appreciate a pull request introducing a Kotlin extension using Kotlin pairs.