Unlist unlisted in list-extensions

[maxandersen]

jaeger was being listed via listExtensions.

With this fix any extension with a "unlisted" key in metadata gets unlisted.
i.e. the mere presence of the key makes it unlisted.

[maxandersen]

@emmanuelbernard can you just confirm listExtensions should always hide "unlisted" extensions ?
addExtension will actually still work and wondering if should remove extensions completely even in add.

[emmanuelbernard]

listExtension should always excluded the unlisted ones yes.
Likewise partial hit via addExtensions should exclude unlisted.
For a perfect GAV, we should not exclude.

[emmanuelbernard]

and value true I guess.

[maxandersen]

just that technically i can be both true (boolean) or a string 'true'. but sure let me add that together while making add honor it too.

[aloubyansky]

I agree with Emmanuel's remark. Let's check for the value of unlisted.

[maxandersen]

I've updated to have check be explicit for "true" or true and addExtension now ignores unlisted unless there is an exact match on artifactId (it never took into account groupid - something we probably want to fix/cleanup in future).