## What is the purpose of the change

Fixes `make format`, needed `mvdan.cc` added to tools directory.

## Brief Changelog

* Add mvdan.cc/gofumpt to tools folder
* Restrict it to only run on `app/ x/ ante/`, it has this annoying problem that it cannot run on the entire root folder because it reads the `.git` folder. It inherits the problem from `gofmt` that it cannot ignore a particular directory.

## Testing and Verifying

This change is a trivial rework / code cleanup without any test coverage.

## Documentation and Release Note

  - Does this pull request introduce a new feature or user-facing behavior changes? no
  - Is a relevant changelog entry added to the `Unreleased` section in `CHANGELOG.md`? no
  - How is the feature or change documented? Should land into contributing.md once its here

* Delete unused simulator code

* Add hourly epochs to the x/epochs DefaultGenesis

* Add changelog

* Delete the unused x/gamm/simulation folder

* Fix epochs module tests for updated DefaultGenesis