Unify time measuring units in all implementations

[vikman90]

After researching #2, we discovered that the following implementations were reporting the time in milliseconds:

• JavaScript
• Java
• C#
• Python
• PHP

This was causing an unfair advantage to these languages in the comparison.

Fix proposed

Every implementation must report the execution time in milliseconds at the testing output.

[vikman90]

Implementation	Steps/ms (max)	Steps/ms (avg)	Discards/ms (max)	Discards/ms (avg)
C++	496,40	125,20	30.023,02	10.715,92
Rust	355,49	93,10	24.365,76	5.793,85
Go	310,16	72,91	17.422,22	1.282,14
JavaScript	124,19	29,49	3.361,07	1.629,27
C#	46,36	22,65	4.853,36	1.263,75
Java	21,21	13,26	4.176,81	1.047,12
Python	13,39	2,17	704,93	519,03