Merge branch 'update-influx-docs-management-repo' into 'master'

Use influxdb-management for managing InfluxDB

## What does this MR do?

This updates the InfluxDB documentation so it suggests using https://gitlab.com/gitlab-org/influxdb-management instead of requiring users to manually copy-paste queries into an InfluxDB shell.

## Are there points in the code the reviewer needs to double check?

Mostly spelling and if the writing style makes sense.

## Why was this MR needed?

The same list of queries was duplicated in multiple places and it was hard to manually keep this up to date.

## Does this MR meet the acceptance criteria?

- [x] ~~[CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added~~ Not really tied into a version
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !4875