Add adminx.APIKeys for allocating organization api keys for Autojoin API

[stephen-soltesz]

This change adds a new type to the adminx package for managing API keys to the Autojoin API.

With this functionality, it will be possible for the orgadm command to allocate and produce an API key for new (or existing) organizations.

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This change is 

[coveralls]

Pull Request Test Coverage Report for Build 11557947631

Details

• 42 of 42 (100.0%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.04%) to 98.888%

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Totals
Change from base Build 11463171052:	0.04%
Covered Lines:	1156
Relevant Lines:	1169

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💛 - Coveralls