Add the option to fetch the paramters as Map from Selector

[vanny96]

Describe the feature

The rust API for the Selector class allows to retrieve the paramaters as a map with the parameters_map method. It would be nice to have such a feature in the kotlin API.

This could be implemented either through the JNI, reusing the existing logic used in Rust, or reimplemented in Kotlin using libraries such as httpcomponents-client.

Any opinions on this?

[DariusIMP]

Hi! Thanks for reporting this, indeed that's one of the features that are missing. There are a couple of other functionalities on the Selector that need to be implemented, I opened issue #67 for that.

or reimplemented in Kotlin using libraries such as httpcomponents-client

I'd rather minimize the reliance on external libs if possible. I haven't yet reviewed your PR, will do so now :)