Junit5: Provide Kotlin extension function for ArgumentsAccessor

[juergenzimmermann]

When using JUnit 5.2.0-RC1 with Kotlin, you have to write e.g.:

val date = args.get(2, LocalDate::class.java)

It would be smoother when one could write (as e.g. in https://github.com/junit-team/junit5/blob/r5.2.0-RC1/junit-jupiter-api/src/main/kotlin/org/junit/jupiter/api/Assertions.kt#L96):

val date = args.get<LocalDate>(2)

[hutaidavid]

Hello!
I would like to work on this issue if it is not a problem and be part of the contribution.

[wilder]

Hello, I'm also interested in working on this issue! How can we proceed?

[marcphilipp]

Let's decide if/how to implement it before getting started. Having said that, I'm all for it.

Can this be implemented as an extension function?

[marcphilipp]

@hutaidavid @WilderPereira Are you still interested in working on this issue?

[wilder]

Yes, I am!

[marcphilipp]

Well then, go for it! 🙂

[marcphilipp]

_in progress_ by @WilderPereira