Does the Telegraf chart need list value defaults for inputs, outputs, and processors?

Hi, I've noticed that the chart for Telegraf includes some default values for inputs, outputs, and processors, e.g.:

https://github.com/influxdata/helm-charts/blob/10fdfe98005d67df5662f40a1ef6db6099ea5e03/charts/telegraf/values.yaml#L147-L151

However, we would like to be able to specify these as maps instead of lists. For example, we may want to have default values for a given output and then be able to override them per environment. If we specify this as a list, then we have to manually supply a full configuration for each environment. This can get really error prone and burdensome across multiple environments with multiple developers.

It seems like the configuration _can_ be specified as a map (which would make sense given the `range` function in Go/Helm) but we constantly get warnings like this when using a map:

```sh
coalesce.go:301: warning: destination for telegraf.telegraf.config.inputs is a table. Ignoring non-table value ([map[statsd:map[allowed_pending_messages:10000 metric_separator:_ percentile_limit:1000 percentiles:[50 95 99] service_address::8125]]])
coalesce.go:301: warning: destination for telegraf.telegraf.config.outputs is a table. Ignoring non-table value ([map[influxdb:map[database:telegraf urls:[http://influxdb.monitoring.svc:8086]]]])
coalesce.go:301: warning: destination for telegraf.telegraf.config.inputs is a table. Ignoring non-table value ([map[statsd:map[allowed_pending_messages:10000 metric_separator:_ percentile_limit:1000 percentiles:[50 95 99] service_address::8125]]])
coalesce.go:301: warning: destination for telegraf.telegraf.config.outputs is a table. Ignoring non-table value ([map[influxdb:map[database:telegraf urls:[http://influxdb.monitoring.svc:8086]]]])
coalesce.go:301: warning: destination for telegraf.telegraf.config.inputs is a table. Ignoring non-table value ([map[statsd:map[allowed_pending_messages:10000 metric_separator:_ percentile_limit:1000 percentiles:[50 95 99] service_address::8125]]])
coalesce.go:301: warning: destination for telegraf.telegraf.config.outputs is a table. Ignoring non-table value ([map[influxdb:map[database:telegraf urls:[http://influxdb.monitoring.svc:8086]]]])
```

This is probably due to trying to merge a map into a list - the list values end up being discarded. And while this is fine for now, we're wondering what potential changes to Go/Helm could cause problems in the future when trying this operation.

Any chance that inputs/outputs/processors could _not_ have a list as a default specified? The ones in there right now don't seem to make sense anyway.

Start with charts/telegraf/values.yaml at the referenced inputs, outputs, and processors defaults, then inspect the chart templates that range over telegraf.config. Verify how Helm coalesces map and list values. Done means map-based overrides work without the reported warnings and the existing chart configuration remains valid.

Written by the indexing model from the issue text.