Standardize plugin name

[aetter]

As noted in https://github.com/opendistro-for-elasticsearch/security-kibana-plugin/issues/19, the alerting plugin uses a dash, whereas everything else uses an underscore:

./bin/elasticsearch-plugin list
opendistro_alerting
opendistro_performance_analyzer
opendistro_security
opendistro_sql

./bin/kibana-plugin list
[email protected]
[email protected]

Expected behavior would be [email protected] (or a dash if we can get all plugins to switch).

[mihirsoni]

@aetter list CLI is being handled by Kibana and not by us so can't remove the version. Regarding - and _ IMO, we should be using - thats convention for any JS packages.

[aetter]

Hi @mihirsoni, no objection to using - for all plugins, I just want them to all use the same convention.