[OTLP] Support for exporting entire instrumentation scope as tags

[bezmax]

I have found a configuration parameter instrumentation_scope_metadata_as_tags, which sounds like it would take entire instrumentation scope and ship it as tags. However, looking at the code, it appears it only copies instrumentation scope's metadata..

Would it be possible to implement similar configuration value, but which would export all instrumentation scope attributes as tags? Similar to resource_attributes_as_tags.

Otherwise, we have to copy all the instrumentation scope attributes into resource attributes right now.

Thanks!