Replace master and slave references in Telegraf configs

## Feature Request

Opening a feature request kicks off a discussion.

### Proposal:
I would like to ask that the master/slave references be replaced in the Telegraf configs with more appropriate terms.

### Current behavior:
To use the Telegraf service we must set configuration values that introduce the word "slave" into our repo.

### Desired behavior:
Allow callers to use the Telegraf service with more appropriate configuration setting names as suggested in this IETF memo: https://tools.ietf.org/id/draft-knodel-terminology-00.html

### Use case:
Open source project takes dependency on Telegraf but doesn't want to introduce insensitive terms into their own repo.

Start by searching the Telegraf repository for configuration references to "master" and "slave" and inspect the related configuration definitions and callers. The issue does not name specific files, replacement terms, tests, or compatibility requirements; done would require an agreed scope and verification that the affected Telegraf configurations use the approved terminology.

Written by the indexing model from the issue text.