Rewards setup contracts template

[kwhuo68]

Core changes:

Adds the following main contracts:

1. ModuleDepositToken.sol -> represents tokenized deposit into module
2. ModuleTokenFactory.sol -> generates tokenized deposits i.e. ModuleDepositToken
3. ModuleDispatcher.sol -> serves as aggregator/dispatcher, central contract storing module pool metadata
4. ModuleRewardPool.sol -> stores actual share accounting etc. relevant for given reward stream, Synthetix contract fork
5. ModuleRewardFactory.sol -> generates reward contracts for each module pool i.e. ModuleRewardPool

Interfaces (should be self explanatory):

1. IModule.sol
2. IModuleRewardFactory.sol
3. IModuleRewardPool.sol
4. IModuleTokenFactory.sol
5. IModuleTokenMinter.sol

Notes: Still some implementation edits and TODOs which I've marked, also need to integrate and write tests etc