Add search filters for modern editions, IIIF bounding boxes and lyrical text

[craigsapp]

Implemented with commit https://github.com/craigsapp/website-polish-scores/commit/ff84a1f1ed9d54a1849de20b84c8b621f4b99c8e

There are three added keyboard commands on the browse page that can select groups of scores:

Keyboard shortcut	Meaning
m	toggle selection of scores that contain modern editions
i	toggle selection of scores that contain IIIF bounding boxes
x	toggle selection of scores that contain lyrical text

Example:

pressing m will only show scores that have non-automatic modern editions:

(currently 449).

Here is a particular score with modern edition:

polishscores.org/?id=17xx:1047

The diplomatic/original edition:

The modern edition (by clicking on the O in the top toolbar: