Kibana version: 7.17.3 and 8.2.0

Elasticsearch version: Matches Kibana

Server OS version: cloud.elastic.co

Browser version: Firefox

Browser OS version: MacOS

Original install method (e.g. download page, yum, from source, etc.): cloud.elastic.co

Describe the bug:
The code folding and syntax highlight of Dev Tools' Console are there, but the line numbers are missing.

Steps to reproduce:

1. Kibana (menu) > Management (header) > Stack Management (link) > Alerts and Insights (header) > Watcher (link)
2. Create (button) > Created advanced watch (option)
3. Create advanced watch (screen) > Edit (tab)
   i. Relative path /app/management/insightsAndAlerting/watcher/watches/new-watch/json
4. Field "Watch JSON"

Expected behavior:
Line numbers like Dev Tools' Console.

Screenshots (if relevant):

7.17.3

8.2.0

Errors in browser console (if relevant): N/A

Provide logs and/or server output (if relevant): N/A

Any additional context:
Any where there is multi-line input or output that is JSON or other code, it is helpful to include line numbers. They make team work easier when describing which line within the large block of text you are referring to. Much easier then describing the location relative to a users cursor or mouse pointer.