Problem: no upgrade handler for v2.0.0-testnet3

[thomas-nguy]

👮🏻👮🏻👮🏻 !!!! REFERENCE THE PROBLEM YOUR ARE SOLVING IN THE PR TITLE AND DESCRIBE YOUR SOLUTION HERE !!!! DO NOT FORGET !!!! 👮🏻👮🏻👮🏻

PR Checklist:

• Have you read the CONTRIBUTING.md?
• Does your PR follow the C4 patch requirements?
• Have you rebased your work on top of the latest master?
• Have you checked your code compiles? (make)
• Have you included tests for any non-trivial functionality?
• Have you checked your code passes the unit tests? (make test)
• Have you checked your code formatting is correct? (go fmt)
• Have you checked your basic code style is fine? (golangci-lint run)
• If you added any dependencies, have you checked they do not contain any known vulnerabilities? (go list -json -m all | nancy sleuth)
• If your changes affect the client infrastructure, have you run the integration test?
• If your changes affect public APIs, does your PR follow the C4 evolution of public contracts?
• If your code changes public APIs, have you incremented the crate version numbers and documented your changes in the CHANGELOG.md?
• If you are contributing for the first time, please read the agreement in CONTRIBUTING.md now and add a comment to this pull request stating that your PR is in accordance with the Developer's Certificate of Origin.

Thank you for your code, it's appreciated! :)

[codecov]

Codecov Report

Merging #842 (e504a96) into main (9567c36) will decrease coverage by 1.71%.
The diff coverage is 0.00%.

❗ Current head e504a96 differs from pull request most recent head acf716b. Consider uploading reports for the commit acf716b to get more accurate results

@@            Coverage Diff             @@
##             main     #842      +/-   ##
==========================================
- Coverage   36.47%   34.76%   -1.71%     
==========================================
  Files          56       30      -26     
  Lines        4058     1559    -2499     
==========================================
- Hits         1480      542     -938     
+ Misses       2407      960    -1447     
+ Partials      171       57     -114     

Impacted Files	Coverage Δ
app/upgrades.go	0.00% <0.00%> (ø)
app/export.go	0.00% <0.00%> (ø)
x/cronos/types/keys.go	0.00% <0.00%> (ø)
x/cronos/types/codec.go	0.00% <0.00%> (ø)
x/cronos/keeper/grpc_query.go	0.00% <0.00%> (ø)
versiondb/client/to_versiondb.go
versiondb/client/print.go
versiondb/extsort/sort.go
versiondb/memiavl/tree.go
... and 24 more