This commit enhances the ClusterStatsNodes response to include global
processor usage stats on a per-processor basis.
example output:
```
...
"processor_stats": {
"gsub": {
"count": 0,
"failed": 0
"current": 0
"time_in_millis": 0
},
"script": {
"count": 0,
"failed": 0
"current": 0,
"time_in_millis": 0
}
}
...
```
The purpose for this enhancement is to make it easier to collect stats on how specific processors are being used across the cluster beyond the current per-node usage statistics that currently exist in node stats.
Closes#46146.
523cb23e02