Feat simplify onAfterAllocateLQTY hook

[GalloDaSballo]

• Add assert for onAfterAllocateLQTY to ensure the code works as the spec

• Rewrite the code to be easier to read

• Simplify the code

• Implement tests for it

• E2E / Fuzz for reverts

• Invariant Tests for accounting and reverts

• Fix Tests
  These tests are currently broken:

Ran 8 test suites in 2.22s (2.21s CPU time): 37 tests passed, 6 failed, 0 skipped (43 total tests)

Failing tests:
Encountered 6 failing tests in test/BribeInitiativeAllocate.t.sol:BribeInitiativeAllocateTest
[FAIL. Reason: assertion failed: 2001000000000000000000 != 1000000000000000000] test_onAfterAllocateLQTY_newEpoch_NoVetoToVeto() (gas: 403990)
[FAIL. Reason: assertion failed: 2001000000000000000000 != 1000000000000000000] test_onAfterAllocateLQTY_newEpoch_VetoToNoVeto() (gas: 252067)
[FAIL. Reason: assertion failed: 2001000000000000000000 != 1000000000000000000] test_onAfterAllocateLQTY_newEpoch_VetoToVeto() (gas: 252110)
[FAIL. Reason: assertion failed: 2001000000000000000000 != 1000000000000000000] test_onAfterAllocateLQTY_sameEpoch_NoVetoToVeto() (gas: 355481)
[FAIL. Reason: assertion failed: 2001000000000000000000 != 1000000000000000000] test_onAfterAllocateLQTY_sameEpoch_VetoToNoVeto() (gas: 355460)
[FAIL. Reason: assertion failed: 2001000000000000000000 != 1000000000000000000] test_onAfterAllocateLQTY_sameEpoch_VetoToVeto() (gas: 204028)

I believe they were implemented incorrectly as they were allowing one caller to both vote and veto, but I wanted to make sure.

CC: @jltqy @ColinPlatt

[GalloDaSballo]

I fixed the tests

I believe we should add invariant tests here:

• A user can only have XOR vote or veto for each instance
• Sum of user votes is at most their vote power
• Any user can never reset other users vote power

[GalloDaSballo]

Closing in favour of #13
See my comment there