Improve display text in Stock Movements custom search filter

[jmcameron]

Currently (after PR 6635 ), the display text for the "Input" vs "Output" show up as "Output: No" and "Output: Yes" respectively. See this discussion in the PR.

Ideally (for a user), the display should be something like this: "Input" option selected => Inputs Only "Output" option selected => Outputs Only

But this is a little tricky since the underlying option is "is_exit"...