Upgrade to glimmer-libui-cc-graphs_and_charts 0.1.8 to fix display of grid markers in Metrics graph when max y-axis value exceeds 1 and is a non-Integer

Upgrade to glimmer-libui-cc-graphs_and_charts 0.1.8 to fix display of grid markers in Metrics graph when max y-axis value exceeds 1 and is a non-Integer #99