Remove sdk.Result from application callbacks #215

[smadarasmi]

Description

Closes #215 by removing sdk.Result from the IBC Module
-->

closes: #215

---

Before we can merge this PR, please make sure that all the following items have been
checked off. If any of the checklist items are not applicable, please leave them but
write a little note why.

• Targeted PR against correct branch (see CONTRIBUTING.md)
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• Code follows the module structure standards.
• Wrote unit and integration tests
• Updated relevant documentation (docs/) or specification (x/<module>/spec/)
• Added relevant godoc comments.
• Added a relevant changelog entry to the Unreleased section in CHANGELOG.md
• Re-reviewed Files changed in the Github PR explorer
• Review Codecov Report in the comment section below once CI passes

[colin-axner]

LGTM, this needs a changelog entry and an entry in the migration docs for going from ibc-go 1.0 -> 2.0 (this will not be included in 1.0)

I will try to push these to this branch

[colin-axner]

I was unable to push to your branch so I made a pr

Thanks for the contribution

[smadarasmi]

@colin-axner Thanks for the prompt feedback. I've merged ur PR into this branch. Please let me know if any other issues.

[colin-axner]

Thanks again for the contribution @smadarasmi! The pr is ready for auto merge