Fix CMS support for PR #351

[jalsol]

Description

Type of change: bug fix

What

Fix CMS support by including another regex. Also, change the method of getting the file name to test.

Why

The old regex supported CMS. The current tests fail in this case (i.e. both CMS input and output files are recognized as Polygon input files).

How Has This Been Tested?

Tested on local version of VNOJ, including previous tests and a Free Contest test data (in: CLIMBING/input.*, out: CLIMBING/output.*).

Checklist

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[leduythuccs]

LGTM