MISC: Add generic type as returned type for action and checking

[catloversg]

Edit: Originally, this PR moves Availability and Attempt to a more generic place. After discussing, we decide to create a new type instead of moving Availability and Attempt.

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In the past, we sometimes used a returned string to indicate success/failure. For example:

• purchaseAugmentation (src\Faction\FactionHelpers.tsx) returns a string. The caller will check if it starts with "You purchased" to see whether it succeeds.
• purchaseUnlock and purchaseUpgrade return strings to indicate a failure.

When refactoring those functions, I use IReturnStatus (src\types.ts), then I see Availability and Attempt. I think these two types are pretty nice and can be used outside Bladeburner. This PR moves them to src\types.ts.