feat: Add new Grafana dashboards: Aggregated Reports, Project Insights, and User Insights

[davidpepm]

Description

This pull request adds three new Grafana dashboards to the AI DIAL Realtime Analytics project as part of the requirements outlined in [Issue #62](#62).

The new dashboards are as follows:

1. DIAL Analytics Aggregated Report: Focuses on aggregated metrics, providing insights derived from pre-aggregated data for performance optimization.
2. DIAL Project Insights: Offers detailed analytics at the project level, enabling better monitoring and understanding of project-specific metrics.
3. DIAL User Insights: Provides user-level analytics to track and analyze individual user behavior and contributions.
4. DIAL Cost Insights: This dashboard provides metrics on cost on a monthly basis.

Dependencies

This PR is dependent on the following pull request in the InfluxData Helm Charts repository:
- [PR #692](influxdata/helm-charts#692): Adds the required buckets and tasks to support the new Grafana dashboards.
This pull request must be merged before this one can be fully functional.
Dependencies are specified in the influxdb/README.md

2. Updated the project documentation (README.md) to reflect the addition of these dashboards.

Testing

Please ensure the following:

• All pre-requisite dependencies from the InfluxDB setup are correctly deployed and functional.
• Grafana is configured to load these new dashboards and displays the expected data as visualized.

Issue Reference

Closes [Issue #62](#62) once merged.

Notes

These dashboards rely on aggregated data for improved performance. > Ensure the required changes in the InfluxDB Helm Chart repository have been deployed and tested before integrating this PR.

[davidpepm]

Documentation and setup instructions are added for enabling the aggregated Grafana dashboards in the AI DIAL Realtime Analytics project.

What's included:
New influxdb/README.md
Contains detailed steps for:

Manually creating required InfluxDB buckets (default_agg_*)

Importing scheduled Flux tasks (aggregate_data, monthly_agg) using the Influx CLI

Explains bucket purpose, retention policy, and usage in dashboards

Updated root README.md

Improved the Aggregated Dashboards (Optional) section

References the influxdb/README.md for setup details

Note:
These setup steps are manual and must be performed via CLI or UI. Helm does not provision these automatically.

Let me know if any clarification is needed or if you'd prefer to automate some of this in the future.