We put `cancun` as evm version into the foundry toml by mistake and
ended up building on top of it with certain assumptions.
Turns out that the network we're deploying to does not support that
version so we have to compile with `paris`.
This however, also requires a downgrade of the open zeppelin libraries,
which in turn requires changes in our code base. Primarily related to
initialization of `OwnableUpgradeable` and upgrades via UUPSUpgradeable.
This commit makes all the necessary changes.
This commit introduces upgradeability of the `RewardsStreamerMP`
contract by leveraging the UUPS pattern.
This means, for deployment, we have to first deploy an instance of
`RewardsStreamerMP` contract as a "template" logic contract and then
create a ERC1967Proxy that points to it.
The proxy ensures the implementation address is stored in a
deterministic storage slot.
This will later be leveraged by the `StakeVault` contract to implement
the functionality to leave the system in case there was a malicious
upgrade.
Closes#22
