Obsolete searchTest.* files should be removed

[martindholmes]

We have these two files:

js/searchTest.html js/seartchTest.js

which have not been touched since 2019, and I believe are only initial experiments superceded by our current test system. I don't believe they're used for anything, and they still retain obsolete camel-case @data-* attribute, which we've obsoleted elsewhere. I believe they should be deleted from both the dev and the release-1.4 branches.