migration(testnet): add v7 migration for moving inacessible faucet address

[danburck]

Description

This PR migrates the testnet faucet balance.

Closes ENG-151: https://linear.app/evmos/issue/ENG-151/migrate-inaccessible-balance-of-secp-faucet-account-to-new-address

[codecov]

Codecov Report

Merging #760 (72cdbc3) into main (0748677) will decrease coverage by 0.17%.
The diff coverage is 44.11%.

❗ Current head 72cdbc3 differs from pull request most recent head f261fae. Consider uploading reports for the commit f261fae to get more accurate results

@@            Coverage Diff             @@
##             main     #760      +/-   ##
==========================================
- Coverage   81.47%   81.30%   -0.18%     
==========================================
  Files         125      126       +1     
  Lines        7159     7193      +34     
==========================================
+ Hits         5833     5848      +15     
- Misses       1187     1204      +17     
- Partials      139      141       +2     

Impacted Files	Coverage Δ
app/upgrades/v6/upgrades.go	11.90% <ø> (ø)
app/upgrades/v7/upgrades.go	25.00% <25.00%> (ø)
app/app.go	85.28% <90.00%> (+0.06%)	⬆️