[FEATURE] DimensionRegexps support for AppRunner

[meesns]

Is there an existing issue for this?

• I have searched the existing issues

Feature description

Currently, there is no (i believe) option to filter the metrics returned for the AWS/AppRunner namespace. Configuring the DimensionRegexps we would be able to filter metrics returned from this namespace.

I would be willing to contribute, if needed.

What might the configuration look like?

Something like:

      DimensionRegexps: []*regexp.Regexp{
          regexp.MustCompile(":service/(?P<ServiceName>[^/]+)/(?P<ServiceId>[^/]+)$"),
      }

Anything else?

No response