refactor tests for cosmwasm/wasm/v1/tx.proto other than TestClearAdmin (

#100)

* refactor: refactor TestInstantiateContract

* refactor: refactor TestInstantiateContract2

* refactor: refactor TestMigrateContract

* refactor: refactor TestExecuteContract

Value with destination as key cannot be tested
because it is a different value for each execution

* refactor: rename a valuable name

* perf: use createMsgEvent

* chore: add this pr to changelog

* test: add the test case to TestStoreCode

* fix: use ctx.CacheContext()

* fix: delete unnecessary code and add the test case for response check

* fix: add the Index flag and make format

* fix: apply createMsgEvent() to TestUpdateAdmin()

* fix: Set untested fields to nil

* chore: add the comment to TestExecuteContract about
the hackatom contract event

* fix: fix specs of TestExecuteContract for destionation address

* chore: fix pr title and apply that fix to the changelog

* chore: fix pr title and change.log

CHANGELOG.md

@@ -27,6 +27,7 @@
 * [\#68](https://github.com/Finschia/wasmd/pull/68) add an integration test for UpdateAdmin
 * [\#99](https://github.com/Finschia/wasmd/pull/99) format test files
 * [\#98](https://github.com/Finschia/wasmd/pull/98) refactor TestStoreAndInstantiateContract
+* [\#100](https://github.com/Finschia/wasmd/pull/100) refactor tests for cosmwasm/wasm/v1/tx.proto other than TestClearAdmin
 
 ### Bug Fixes
 * [\#62](https://github.com/Finschia/wasmd/pull/62) fill ContractHistory querier result's Updated field