Use detokenization amount from tx response

[sampocs]

Closes: #XXX

Context

Similar to unbondings, detokenization ICAs have the potential to return slightly less tokens than were specified in the tx due to rounding imprecision in the SDK (see #933 for more context). This can create a small difference in stride's internal record keeping (on the order of < 10uatom).

However, the number of tokens that winds up being detokenized is part of the tx response, so we can just use that value instead, which will prevent the rounding imprecision from being reflected in record keeping.

Brief Changelog

• Updated detokenize callback to use the response from the RedeemTokensForShares message

Author's Checklist

I have...

• Run and PASSED locally all GAIA integration tests
• If the change is contentful, I either:
  • Added a new unit test OR
  • Added test cases to existing unit tests
• OR this change is a trivial rework / code cleanup without any test coverage

If skipped any of the tests above, explain.

Integration Tests

integration_tests.bats
 ✓ [INTEGRATION-BASIC-GAIA] host zones successfully registered
 ✓ [INTEGRATION-BASIC-GAIA] ibc transfer updates all balances
 ✓ [INTEGRATION-BASIC-GAIA] liquid stake mint and transfer
 ✓ [INTEGRATION-BASIC-GAIA] tokens on GAIA were staked
 ✓ [INTEGRATION-BASIC-GAIA] LSM liquid stake
 ✓ [INTEGRATION-BASIC-GAIA] LSM liquid stake with slash query
 ✓ [INTEGRATION-BASIC-GAIA] packet forwarding automatically liquid stakes
 ✓ [INTEGRATION-BASIC-GAIA] redemption works
 ✓ [INTEGRATION-BASIC-GAIA] claimed tokens are properly distributed
 ✓ [INTEGRATION-BASIC-GAIA] rewards are being reinvested, exchange rate updating
 ✓ [INTEGRATION-BASIC-GAIA] rewards are being distributed to stakers

Documentation and Release Note

• Does this pull request introduce a new feature or user-facing behavior changes?
• Is a relevant changelog entry added to the Unreleased section in CHANGELOG.md?
• This pull request updates existing proto field values (and require a backend and frontend migration)?
• Does this pull request change existing proto field names (and require a frontend migration)?
  How is the feature or change documented?
  • not applicable
  • jira ticket XXX
  • specification (x/<module>/spec/)
  • README.md
  • not documented

[ethan-stride]

LGTM