chore: update `Makefile` and add tools dependencies

[aljo242]

• Uses gofumpt for formatting instead of gofmt.
• Updates the Makefile to automatically install the required dev tools for working on the repo (gofumpt, goimports, golangci-lint).
• Adds the tools/tools.go file to add the dev tools to the go.mod, allowing them to be requirements of our package.
• Runs basic make lint and make format targets

[codecov[bot]]

Codecov Report

Merging #943 (3d0bfc7) into develop (10a2cfe) will increase coverage by 0.00%. The diff coverage is n/a.

@@           Coverage Diff            @@
##           develop     #943   +/-   ##
========================================
  Coverage    10.60%   10.60%           
========================================
  Files          328      328           
  Lines        75537    75537           
========================================
+ Hits          8007     8009    +2     
+ Misses       67340    67339    -1     
+ Partials       190      189    -1     

Impacted Files	Coverage Δ
x/claim/types/params.go	60.86% <ø> (ø)
x/campaign/simulation/store.go	82.43% <0.00%> (+1.35%)	:arrow_up: