Option for read-only user access Oxidized configs

[bnoack-stepcg]

Created option in oxidized settings to allow read only users to access Oxidized configs.

Please give a short description what your pull request is for

DO NOT DELETE THE UNDERLYING TEXT

Please note

Please read this information carefully. You can run ./lnms dev:check to check your code before submitting.

• Have you followed our code guidelines?
• If my Pull Request does some changes/fixes/enhancements in the WebUI, I have inserted a screenshot of it.
• If my Pull Request makes discovery/polling/yaml changes, I have added/updated test data.

Testers

If you would like to test this pull request then please run: ./scripts/github-apply <pr_id>, i.e ./scripts/github-apply 5926
After you are done testing, you can remove the changes with ./scripts/github-remove. If there are schema changes, you can ask on discord how to revert.

[CLAassistant]

All committers have signed the CLA.

[Jellyfrog]

There is a RBAC system now in librenms and we would like to start using that for authorization

[electrocret]

LGTM. Seems like an acceptable stop-gap till we get RBAC fully developed.

[electrocret]

Just noticed Jelly's comment. I guess RBAC is further along than I thought.