Implement Metrics Reporting for Lox

From the Lox Roadmap we want to include strategic reporting of metrics in our Lox deployment so that we are able to determine the effectiveness of Lox. The minimum metrics to measure are the following:

• Prometheus metrics for counts of how often each library function is called from distributor
• How many bridges are in each rank
• Blockages from deployed bridgestrap instance
• Remaining capacity (or if/when we run out of bridges to hand out to open inv)

Discussion, development of these and additional metrics to include in the initial deployment will be tracked in this issue.