Consolidated application state store.

[tonyanziano]

Resolves #1697

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This is a huge PR, so here are a couple of notes:

• The real magic happens in forwardToMain.ts, forwardToRenderer.ts, & store.ts on both main and client
• The reducers & actions had to be combined and duplicated on both sides. I'm thinking that in a future PR, these could all be moved to the /app/shared/ package so that we only need one copy of each reducer and set of actions
• Removed a lot of unnecessary code calling between main / renderer to sync data
• Removed some unused / unnecessary reducer & action code
• Added missing tests for all state actions (planning to add tests for all state reducers) DONE

[cwhitten]

@tonyanziano from the description it looks like you still plan to implement some additional tests?

(planning to add tests for all state reducers)

[tonyanziano]

@cwhitten Correct, but I was thinking of including them in a separate PR to keep this one as small as possible.

I can include them in this PR though if you'd prefer.

[coveralls]

Coverage increased (+2.4%) to 65.323% when pulling 452a118 on toanzian/state into 54e8cbe on master.

[tonyanziano]

Reducer tests have been added.