This is a follow up to #3861 and requests from users such as #3959 (comment).

Currently, exponential histograms can only be configured at the registry level for the OTLP registry via OtlpConfig. This is fine for users who want to use exponential histograms for everything that has percentileHistogram enabled. However, more fine grained control gives more flexibility.

As a workaround, configuring any SLO on a meter's DistributionStatisticConfig will cause exponential histograms to not be used (they don't support arbitrary additional buckets).

Another aspect of configuration would be the (max) bucket count, which again is currently controlled by OtlpConfig for all meters in the registry.