Exact histogram for large numeric measurements

On numeric measurements with more than 500 points, the control chart histogram was built from a sample of the data, so the distribution was approximate and rare out-of-spec values could be missing from the bars while the OOS counter showed them.

• Improved the numeric histogram to show the exact distribution over all points, matching the boolean and string charts
• Fixed out-of-spec outliers disappearing from the histogram on large datasets; the value range now always covers them
• Fixed the histogram tooltip ratio, which could overstate bin proportions on sampled data