refactor[test]: add sanity checks to abi decode tests

[cyberthirst]

What I did

• added sanity checks to abi decode tests to ensure that we're never failing on calldatasize
• also split the creation of payload into two parts when calling target contract with low-level msg_call to increase readability
• depends on https://github.com/vyperlang/vyper/pull/4091 because the tests from there were also refactored

How I did it

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[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 90.42%. Comparing base (69e5c05) to head (c64eea6).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #4096 +/- ## ========================================== - Coverage 91.32% 90.42% -0.90% ========================================== Files 109 109 Lines 15557 15557 Branches 3416 3416 ========================================== - Hits 14207 14067 -140 - Misses 920 1032 +112 - Partials 430 458 +28 ```

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