Clear registered vocab when skill is unloaded

[forslund]

Description

This adds a search and destroy method moving through the Adapt Trie removing any keywords belonging to the skill when skill is shutdown.

This should fix 50% of the issues described in #2866.

How to test

• Start Mycroft
• Enter the word jokes in the CLI and assert you get a suitably bad joke
• Take the joke skill's Joke.voc vocab and remove the word jokes then save the file
• Skill will reload
• Enter the word jokes again and assert that Mycroft don't know what your talking about
• Enter joke and make sure that works as expected

Contributor license agreement signed?

CLA [ yes ]

[devops-mycroft]

Voight Kampff Integration Test Failed (Results).
Mycroft logs are also available: skills.log, audio.log, voice.log, bus.log, enclosure.log

[JarbasAl]

shouldn't this be made against adapt repo instead? feels like the find_type method belongs somewhere in there

if its faster it can be merged as a workaround, but maybe leave a TODO + Issue in adapt repo

[devops-mycroft]

Voight Kampff Integration Test Failed (Results).
Mycroft logs are also available: skills.log, audio.log, voice.log, bus.log, enclosure.log

[forslund]

I'm still pondering on how to do it best in adapt. Possibly a search/remove using regex / globbing matches.

Adapt has by tradition no remove code so we'll see how well those patches are received :)

[forslund]

Opened adapt PR MycroftAI/adapt#122

[devops-mycroft]

Voight Kampff Integration Test Succeeded (Results)

[forslund]

Going to close this, got some excellent feedback over at the Adapt PR telling me why this is not a good idea and will iterate on it there.