[Instance Statistics] Tooltip values should have thousands delimiters

Problem to solve

In Instance Statistics, you can mouseover the charts to see the values. Currently these values do not have thousands delimiters, which can make them a bit difficult to read.

This was spotted by @ahegyi and reported in Slack#g_manage_optimize.

Screenshot

Proposal

In Instance Statistics, in the mouseover chart tooltips, the numbers should have thousands delimiters.