[resource] add 'next-pool' field support to Pool

[maksym-nazarenko]

This PR adds support of next-pool field to the pool resource.
Closes #23

[maksym-nazarenko]

@ddelnano during investigation, I found that client.Marshal() func skips empty string so it is not possible to set any string value to an empty string via API.

[ddelnano]

@maksym-nazarenko apologies for the long delay on this. I was traveling and got engaged.

during investigation, I found that client.Marshal() func skips empty string so it is not possible to set any string value to an empty string via API.

Regarding that, maybe the Marshal interface should allow something like omitempty like the json package provides? That would allow us to disambiguate a case like this, right?

I'll merge this for now, but I'd like to here your thoughts about the above.

[maksym-nazarenko]

apologies for the long delay on this

no worries Dom, I found you work really useful so I'm happy to help you with enhancement of this provider

I was traveling and got engaged

my congratulations to you 🎉

Regarding that, maybe the Marshal interface should allow something like omitempty like the json package provides? That would allow us to disambiguate a case like this, right?

yes, in theory, but sometimes you mean omitempty to skip this field entirely during Update and sometimes you want exactly "" (empty string) to be set.
Frankly speaking, I have no good idea how to distinguish those to cases at the moment 🤷
Anyway, let's keep it in mind when touch Marshal next time

[ddelnano]

I really appreciate your work on this and so just want to continue to make sure that my slow replies don't make you feel that the changes aren't appreciated! And thanks for the congratulations!

Yep, that makes sense and I agree we can keep that in mind for the future 👍