Add next-metrics instrumentation to search route

Just going to try a single route to prove it works ok.

Logs the following :- 

```
123.localhost.dobi._.express.http.res.status_2xx_response_time.mean null
123.localhost.dobi._.express.http.res.status_2xx_response_time.stdDev null
123.localhost.dobi._.express.http.res.status_2xx_response_time.min null
123.localhost.dobi._.express.http.res.status_2xx_response_time.max null
123.localhost.dobi._.express.http.res.status_2xx_response_time.sum null
123.localhost.dobi._.express.http.res.status_4xx_response_time.mean null
123.localhost.dobi._.express.http.res.status_4xx_response_time.stdDev null
123.localhost.dobi._.express.http.res.status_4xx_response_time.min null
123.localhost.dobi._.express.http.res.status_4xx_response_time.max null
123.localhost.dobi._.express.http.res.status_4xx_response_time.sum null
123.localhost.dobi._.express.http.res.status_5xx_response_time.mean null
123.localhost.dobi._.express.http.res.status_5xx_response_time.stdDev null
123.localhost.dobi._.express.http.res.status_5xx_response_time.min null
123.localhost.dobi._.express.http.res.status_5xx_response_time.max null
123.localhost.dobi._.express.http.res.status_5xx_response_time.sum null
123.localhost.dobi._.express.http.res.status_2xx.count 0
123.localhost.dobi._.express.http.res.status_3xx.count 0
123.localhost.dobi._.express.http.res.status_4xx.count 0
123.localhost.dobi._.express.http.res.status_5xx.count 0
123.localhost.dobi._.system.os.cpus 4
123.localhost.dobi._.system.procees.uptime 5
123.localhost.dobi._.system.process.version.major 0
123.localhost.dobi._.system.process.version.minor 10
123.localhost.dobi._.system.process.version.patch 31
123.localhost.dobi._.system.process.mem_process_rss 81911808
123.localhost.dobi._.system.process.mem_process_heapTotal 65712248
123.localhost.dobi._.system.process.mem_process_heapUsed 35010240
123.localhost.dobi._.system.process.load_average_1m 2.14990234375
```