[receiver/azuremonitorreceiver] feat: Allow to not split result by dimension

[celian-garcia]

Recreated from a diffferent fork. Context: #36240

Description

Currently there is a mechanism allowing to split the result by dimension, thanks to a filter param hack.
This is great that all the dimensions are collected as labels in the metrics, but for some resources types it could be unwanted. In cause some concern about cardinality, or continuity of the queries between one version to another (e.g with prometheus exporter, if one does not do a "sum by ..." and the otelcol version is updated, the query can display different results)

To mitigate that I propose to put an optout for this collection so if we want for some resource types and not for others, we can create two separate receivers for example. Or we completely opt out if we don't want additional labels.

Edit:

After a first review, we agreed on the fact that it could do a bit more like allowing us to specify a list of dimensions for a particular metric.
e.g from added documentation

receivers:
  azuremonitor:
    dimensions:
      enabled: true
      overrides:
        "Microsoft.Network/azureFirewalls":
          # Real example of an Azure limitation here:
          # Dimensions exposed are Reason, Status, Protocol,
          # but when selecting Protocol in the filters, it returns nothing.
          # Note here that the metric display name is ``Network rules hit count`` but it's programmatic value is ``NetworkRuleHit``
          # Ref: https://learn.microsoft.com/en-us/azure/azure-monitor/reference/supported-metrics/microsoft-network-azurefirewalls-metrics
          "NetworkRuleHit": [Reason, Status]

Without this config you won't have the azure_networkrulehit_average_Count metric at all in your results
But with the config we have it with reason and status labels:

# HELP azure_networkrulehit_average_Count
# TYPE azure_networkrulehit_average_Count gauge
azure_networkrulehit_average_Count{azuremonitor_resource_id="/subscriptions/<redacted>/resourceGroups/<redacted>/providers/Microsoft.Network/azureFirewalls/<redacted>",location="<redacted>",metadata_reason="<redacted>",metadata_status="Allow",name="<redacted>",resource_group="<redacted>",type="Microsoft.Network/azureFirewalls"} 21.875
azure_networkrulehit_average_Count{azuremonitor_resource_id="/subscriptions/<redacted>/resourceGroups/<redacted>/providers/Microsoft.Network/azureFirewalls/<redacted>",location="<redacted>",metadata_reason="<redacted>",metadata_status="Deny",name="<redacted>",resource_group="<redacted>",type="Microsoft.Network/azureFirewalls"} 10

Link to tracking issue

Fixes #36611

Testing

Documentation

[github-actions]

This PR was marked stale due to lack of activity. It will be closed in 14 days.

[atoulme]

Written by codeowner, lgtm

[celian-garcia]

@djaglowski @atoulme can be merged. We're using from our fork with great success already.