Stats: Add data on the last 24hours

[bragov4ik]

From backend side (PR):

• approximate data (last data point) is marked with flag
• .proto file diff
• the feature is accessible in staging (https://eth-sepolia.k8s-dev.blockscout.com/stats)
• example of the retrieved flag:

  
  ❯ curl https://stats-sepolia.k8s-dev.blockscout.com/api/v1/lines/accountsGrowth\?from\=2024-06-05

{"chart":[{"date":"2024-06-05","value":"8647713"},{"date":"2024-06-06","value":"8666021","isApproximate":true}]}%

- [backend task FYI](https://github.com/orgs/blockscout/projects/4/views/1?filterQuery=assignee%3Abragov4ik&pane=issue&itemId=59005802)