fix(add_enable_all_disable_all_buttons): this PR adds enable and disable all patterns to the UI to quickly manage all patterns if desired.

[caleyg]

The UI on the page loads if nothing is enabled, DisableAll is disabled, and EnableAll is enabled.

When the EnableAll button is pushed, we show a spinner (this is useful when there is a persistent store on the backend in another PR in this repo.) so that users do not get trigger-happy. The implementation of this spinner is a little hacky. React lifecycles are opinionated on how it re-renders the UI for performance optimization... we trick it by setting a timeout and using the timeout callback.

This is the UI when the page is loaded, and all patterns are enabled. Note the Enable All button is disabled, and the Disable All button is activated. This is so the user doesn't add the same patterns to the same playlist, preventing accidental duplicates.

This is the result of a user clicking on Disable All. Note the Enable All button is activated, and the Disable All button is disabled. The UI reflects nothing is in the current playlist, and the local storage also shows [].

This PR resolves #45

[caleyg]

this will be resolved in this PR #44