build: update go version to 1.19

[ryanchristo]

Description

Ref: regen-network/cosmos-sdk#49

Using go version 1.18 versus 1.19 with cosmos sdk v0.46 will produce different snapshot hashes. This pull request bumps all modules to use go 1.19 and updates the go version check to require go 1.19. Bumping the go version caused a lint warning to become an error so this pull request also replaces the use of io/ioutil with os.

---

Author Checklist

All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.

I have...

• included the correct type prefix in the PR title
• added ! to the type prefix if API or client breaking change
• targeted the correct branch (see PR Targeting)
• provided a link to the relevant issue or specification
• followed the guidelines for building modules
• included the necessary unit and integration tests
• added a changelog entry to CHANGELOG.md
• included comments for documenting Go code
• updated the relevant documentation or specification
• reviewed "Files changed" and left comments if necessary
• confirmed all CI checks have passed

Reviewers Checklist

All items are required. Please add a note if the item is not applicable and please add
your handle next to the items reviewed if you only reviewed selected items.

I have...

• confirmed the correct type prefix in the PR title
• confirmed ! in the type prefix if API or client breaking change
• confirmed all author checklist items have been addressed
• reviewed state machine logic
• reviewed API design and naming
• reviewed documentation is accurate
• reviewed tests and test coverage
• manually tested (if applicable)

[codecov]

Codecov Report

Merging #1689 (2889eb5) into main (807ca0f) will not change coverage.
The diff coverage is 88.88%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1689   +/-   ##
=======================================
  Coverage   72.80%   72.80%           
=======================================
  Files         228      228           
  Lines       13600    13600           
=======================================
  Hits         9901     9901           
  Misses       2967     2967           
  Partials      732      732           

Impacted Files	Coverage Δ
app/utils.go	0.00% <0.00%> (ø)
types/testutil/network/util.go	70.46% <100.00%> (ø)
x/ecocredit/base/client/utils.go	90.62% <100.00%> (ø)
x/ecocredit/basket/client/util.go	100.00% <100.00%> (ø)
x/ecocredit/marketplace/client/util.go	100.00% <100.00%> (ø)

[clevinson]

Ran ack "1\.18" locally to verify there wasn't any extraneous usage of 1.18.

lgtm! thanks @ryanchristo