chore: add block proposal summary panel to block production dashboard (#7692)

**Motivation**
`feat(validator-monitor): Add block proposal summary panels to Grafana
dashboard`



**Description**
This PR adds monitoring for validator block proposal performance .

<!-- A clear and concise general description of the changes of this PR
commits -->

<!-- If applicable, add screenshots to help explain your solution -->
<img width="1388" alt="Screenshot 2025-04-12 at 17 44 16"
src="https://github.com/user-attachments/assets/f5fd7c20-bf4b-403b-9066-791ceb9f9672"
/>


<!-- Link to issues: Resolves #111, Resolves #222 -->

Closes #6724

**Steps to test or reproduce**

<!--Steps to reproduce the behavior:
```sh
git checkout <feature_branch>
lodestar beacon --new-flag option1
```
-->

---------

Co-authored-by: Nico Flaig <nflaig@protonmail.com>

Author: bomanaps

dashboards/lodestar_block_production.json

@@ -1413,38 +1413,14 @@
             "type": "prometheus",
             "uid": "${DS_PROMETHEUS}"
           },
+          "editorMode": "code",
           "exemplar": false,
-          "expr": "lodestar_attached_validators_total_count",
+          "expr": "384*rate(validator_monitor_prev_epoch_block_proposal_summary[$rate_interval])",
           "format": "time_series",
           "instant": false,
           "interval": "",
-          "legendFormat": "",
+          "legendFormat": "{{summary}}",
           "refId": "A"
-        },
-        {
-          "exemplar": false,
-          "expr": "lodestar_attached_validators_finalized_count",
-          "hide": false,
-          "instant": false,
-          "interval": "",
-          "legendFormat": "",
-          "refId": "B"
-        },
-        {
-          "exemplar": false,
-          "expr": "lodestar_attached_validators_missed_count",
-          "hide": false,
-          "interval": "",
-          "legendFormat": "",
-          "refId": "C"
-        },
-        {
-          "exemplar": false,
-          "expr": "lodestar_attached_validators_orphaned_count",
-          "hide": false,
-          "interval": "",
-          "legendFormat": "",
-          "refId": "E"
         }
       ],
       "title": "Attached Validators Block Proposal Data",
@@ -1574,10 +1550,16 @@
       "pluginVersion": "10.4.1",
       "targets": [
         {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "${DS_PROMETHEUS}"
+          },
+          "editorMode": "code",
           "exemplar": false,
           "expr": "lodestar_finalized_attached_validators_count",
           "interval": "",
           "legendFormat": "",
+          "range": true,
           "refId": "A"
         }
       ],