test: add event checking to TestInstantiateContract

[da1suk8]

Description

TestInstantiateContract

https://github.com/Finschia/wasmd/blob/main/docs/proto/proto-docs.md#msginstantiatecontract

This PR adds an integration test for TestInstantiateContract.

This test is based on https://github.com/CosmWasm/wasmd/blob/33df4aeaaa419f6aad07b94d64c0423bee0a2d21/x/wasm/keeper/msg_server_integration_test.go#L827-L897

Checklist:

• I followed the contributing guidelines and code of conduct.
• I have added a relevant changelog to CHANGELOG.md
• I have added tests to cover my changes.
• I have updated the documentation accordingly.
• I have updated API documentation client/docs/swagger-ui/swagger.yaml

[codecov]

Codecov Report

Merging #70 (56dfeb6) into main (484e437) will increase coverage by 0.04%.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #70      +/-   ##
==========================================
+ Coverage   62.28%   62.32%   +0.04%     
==========================================
  Files          80       80              
  Lines        9966     9966              
==========================================
+ Hits         6207     6211       +4     
+ Misses       3432     3429       -3     
+ Partials      327      326       -1     

see 1 file with indirect coverage changes