Add the ability to have plugin aliases

[michaelorr]

There is the ability to alias a command inside a plugin, but there should be a way to alias the plugin name as well.
This would be useful for the poems plugin, for instance many people attempt to do:
!plugins enable haiku but this fails because there is no haiku plugin.
A small tweak to the way in which the operator plugin looks for matches in the plugins listing should make this possible.

[shaunduncan]

Yes, I had this same thought when dealing with plugin helps. This might be difficult though if there isn't a direct mapping from command name and plugin entry point name

[michaelorr]

I wasnt imagining the abilty to auto-map command names to entry point names... but more of a plugin setting
plugin_aliases = ['haiku', 'tanka']
manually defined in the plugins __init__.py...
When helga looks for a plugin matching "some_string" it first looks through the entry points it knows, failing that it looks through the plugin_aliases it knows. So authors could add aliases when they know there may be confusion in the users's mind.
This wouldnt solve the issue of collision at the alias level, but computering is hard™.