Problems
========
There are no monitoring info and alerts regarding stacking router modules state.

Solution
========

Introduce new metrics for SR
----------------------------
Add collecting metrics from KAPI regarding Staking Router modules:
- Total SR count: `/v1/modules` - count item in the result list
- SR count by status: `/v1/modules`, status: `Active | DepositsPaused | Stopped`
- The latest block timestamp by module: `/v1/modules`, field - `lastDepositAt`
- Used keys by SR name: `/v1/modules/keys`

Add new nestjs module in `lido-mev-monitoring/src/jobs/staking-router` to implement collecting beyond metrics.

Introduce new alerts for SR
---------------------------
Add new yaml files:
- `/alerts/mev-monitoring-staking-router.rule.yml`
- `/alerts/mev-monitoring-staking-router.test.yml`

Add the following metrics to these files:
- the latest block timestamp too old: `time() - lido_mev_monitoring_sr_last_deposited_at >= 5 * 60`

Create a new section in Fees-monitoring Dashboard
----

This section will reflect statistics regarding fees, blocks proposals diagrams.