PLA-450, PLA-449: LicensedVideoSwap updates

This updates the underlying query service behind the LicensedVideoSwap tool, and introduces match post-processing in the LVS helper using Jaccard similarity to improve precision.

Jaccard similarity is computed by comparing arrays of stemmed tokens from video titles. In order to do this I have introduced the php-nlp-tools vendor library, a high-quality, modern PHP library for text processing.

Updates for PLA-449 are also included, wherein we constrain the video search results to those videos within a duration range.