feat(om1.1): relax the acceptance rules around unit and total suffixes

This proposal only relaxes the rules on what is acceptable by ingestors.
This allows non Prometheus systems to expose names without suffixes and
still get processed.

Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>

Author: krajorama

docs/specs/om/open_metrics_spec_1_1.md

@@ -146,6 +146,8 @@ Type specifies the MetricFamily type. Valid values are "unknown", "gauge", "coun
 
 Unit specifies MetricFamily units. If non-empty, it MUST be a suffix of the MetricFamily name separated by an underscore. Be aware that further generation rules might make it an infix in the text format.
 
+Ingestors MAY accept MetricFamily name without unit suffix. Be aware that exposing such metrics directly to end-users reduces usability due to confusion about what the metric's unit is.
+
 ##### Help
 
 Help is a string and SHOULD be non-empty. It is used to give a brief description of the MetricFamily for human consumption and SHOULD be short enough to be used as a tooltip.
@@ -488,7 +490,7 @@ A valid example for a foo_seconds metric with a unit of "seconds":
 # UNIT foo_seconds seconds
 ```
 
-An invalid example, where the unit is not a suffix on the name:
+An invalid example (which MAY still be accepted by ingestors), where the unit is not a suffix on the name:
 
 ```
 # TYPE foo counter
@@ -635,6 +637,8 @@ foo 18.0 456
 
 The MetricPoint's Total Value Sample MetricName MUST have the suffix `_total`. If present the MetricPoint's Created Value Sample MetricName MUST have the suffix `_created`.
 
+Ingestors MAY accept MetricPoint Total Value name without the `_total` suffix. Be aware that exposing such metrics directly to end-users reduces usability due to confusion about what the metric's type is.
+
 An example with a Metric with no labels, and a MetricPoint with no timestamp and no created:
 
 ```openmetrics-add-eof