Use a library for reward collection

[enriquefynn]

To ease the cost of deploying a new collector contract, we should decrease the size of its code, but the tradeoff is that we need to do an extra delegate_call to the library when collecting rewards.

[jenpaff]

To ease the cost of deploying a new collector contract, we should decrease the size of its code, but the tradeoff is that we need to do an extra delegate_call to the library when collecting rewards.

How much of a trade-off are we talking?

[enriquefynn]

How much of a trade-off are we talking?

The main functions, from Foundry:

without lib:
createFeeContract: 309633 gas, $31
collectRewards: 42435 gas $4.24

with lib:
createFeeContract: 220584 gas, $22 (-30%)
collectRewards: 43219 gas, $4.32 (+2.9%)

[jenpaff]

just update README, but other than that LGTM