fix: properly update ui on closing epoch flow

[jpangelle]

Description

• Adds more dependencies to the useEffect that executes the loadPool thunk in order to refetch the pool when changes to the epoch flow are made
• Adds another case to the EpochButton component to show a disabled Close epoch button for when an epoch is open

Two caveats:

1. Sometimes it can take absurdly long to eventually rerender to the proper view like (5-10 seconds)
2. For the flow where closing the epoch is automatically executed, the UI does not properly rerender once the 5 minutes pass to go from Lock DAI -> Epoch Executed.

Closes #235

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