feat(ngPluralize): add support for bind-once in `count`

The 1st commit contains the change and test for adding support for `bindOnce` in `count`.
The 2nd commit contains some nimor refactoring (mainly to avoid repetitive actions).

Closes #10004
(Makes #5452 obsolete)
I also want them gone... but they do provide a useful feature of filtering the output of an expression like what @lgalfaso mentioned. But I don't like how they are implemented right now, but also haven't thought of anything better yet.