Registry based config - Part 1

[dakinggg]

Adds the core of the registry system

Along for the ride, adds some __all__s. Will do a follow up PR that goes through and makes sure all the __all__s are correct.

• Manual test all register styles (registry-4-ia776l, temporarily commented out some loggers and registered them through the different registry methods)
• Write stub of the docs section
• Pass through code again

[mvpatel2000]

while we're at it, we should add trailing comma lint @b-chu ?

Mostly looks good to me. not doing detailed pass yet, but I like the design and no major comments. some minor questions mostly for me

[mvpatel2000]

What's the appropriate level for testing here?

[dakinggg]

@mvpatel2000 I did manual test of all the registration methods (see description), and have unit tests for all the registering methods. What other testing are you thinking? I could run the regression tests against this PR, not sure how much that adds though.

[mvpatel2000]

LGTM but would like more eyes on this given big PR.

Do we need to update YAMLs?

[dakinggg]

@mvpatel2000 should not require any yaml updates as the yaml API is not changing.