LP#2053035: return ability to submit OPAC basic search via enter

LP#2053035: return ability to submit OPAC basic search via enter

This patch fixes an issue with the current autosuggest implementation
that prevented submitting the form while focus is on the main
text input.

To test
-------
[1] Apply patch. Do the following tests using both keyboard
    and mouse navigation.
[2] Verify that submitting a search without selecting any
    of the suggested terms works.
[3] Verify that submitting a search after selecting one
    of the suggestions works.
[4] Verify that submitting the search after using the keyboard
    to navigate the selections, but ultimately not choosing
    any of them, works.
[5] Run automated tests, e.g., by running

    npx jasmine Open-ILS/web/opac/tests/autosuggest.spec.module.js

Release-note: Restore ability to submit basic OPAC search by hitting enter in search input.

Signed-off-by: Galen Charlton <gmc@equinoxOLI.org>
Signed-off-by: Jane Sandberg <js7389@princeton.edu>
Signed-off-by: Steven Mayo <smayo@georgialibraries.org>
Signed-off-by: blake <blake@mobiusconsortium.org>