Internally, WA expects extension names to be valid Python identifiers.
When this is not the case, conversion takes place when loading
configuration for the extension (e.g. "trace-cmd" gets converted to
"trace_cmd").
The conversion is intended to be transparent to the user, so
configuration stores values as they are provided by the user, however it
needs to perform the conversion internally, e.g. when querying
ExtensionLoader. This conversion was missing when performing a lookup of
one of the internal structures, which was causing earlier-collected
settings to not be propagated into the final config.
