[Proposal] 'Natural' rounding to improve big numbers readability in dashboard

[electroape]

Rounds the number to improve readability rounding off insignificant part with the rounding error of no more than 0.5%. Examples : 654654 becomes 655000, rounding error 0.05% 12345 becomes 12300, rounding error 0.36% 2345 becomes 2350, rounding error 0.2% 51.8 becomes 52, rounding error 0.39% Visual example in dashboard (numbers are randomized) : https://imgur.com/WznmuTR Code : https://github.com/uz-spark/xmrigCC-fork/commit/3e5945c7e8d86cde9a425c5688e92c7bbed7953b