Optimize the matching of pbs jobs to ARC jobs

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This merge request is automatically copied from !1305 (merged) orginally made by @arcbot
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This merge request is automatically copied from GitHub master pull request https://github.com/nordugrid/arc/pull/14 orginally made by @dvandok
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The original nested loop with linear search was expensive; by sorting the arrays beforehand only a single traversal of both structures simultaneously is required.

Additional info in the writeup here: https://www.nikhef.nl/~dennisvd/arc-infosys-speedup/arc-infosys-speedup.html

This runs in production at Nikhef.