Adds support for value => label definitions in the admin filter options

[maxchirkov]

Hi John,

I never created a pull request on github before, so hopefully I didn't screw anything up.
So, I implemented the solution I described in my last comment here:
#87 (comment)

I wrote a test too, but for some reason the mockBuilder would not execute my method and always returned null, so I had to instantiated the Extended_CPT_Admin::class.

Feel free to make adjustments or reject if this doesn't feel right to you.

Thanks for the consideration.

[johnbillion]

I forgot to say thanks for the PR. I won't have much time to look into this soon but I'll get to it when I can!

[lmartins]

Looking forward to this merge as I'm facing the same issue, where I need the filter value to be a numeric value.

[ibes]

I am running in the same problem that was the reason for the pull request.
What would help to get the issue fixed?

[ibes]

the pull request works well for me.
Thanks

[johnbillion]

I need to check whether there's a chance this breaks other functionality that unintentionally passes an associative array of values, but generally I agree this change makes sense.

[danielpost]

@johnbillion Do you have an idea when this would be considered? I'm running into the exact same issue as others in the associated issue.

[JUVOJustin]

@johnbillion if only the docks are missing would it be able to merge? I would be happy to send you a markdown doc with the adjusted section regarding callback functions.

[vinkla]

@johnbillion, is there anything I can do to get this merged or have a similar implementation approved? I'm here to help 🙋