Refactor account RPCs tests

[jingyi2811]

What kind of PR is this?:

/kind refactor

What this PR does / why we need it:

It’s getting very difficult to maintain side-effect and writing independent tests. Writing a clean and independent test is not easy, it requires a certain mastery with strong testing principles. Refactoring tests in jellyfish-api-core will allow us to have a cleaner testing culture.

Which issue(s) does this PR fixes?:

Fixes #295

Additional comments?:

[defichain-bot]

@jingyi2811: There are no 'kind' label on this PR. You need a 'kind' label to generate the release automatically.

• /kind feature
• /kind fix
• /kind chore
• /kind docs
• /kind refactor
• /kind dependencies

Details

I am a bot created to help the DeFiCh developers manage community feedback and contributions. You can check out my manifest file to understand my behavior and what I can do. If you want to use this for your project, you can check out the DeFiCh/oss-governance-bot repository.

[netlify]

✔️ Deploy Preview for jellyfish-defi ready!

🔨 Explore the source changes: 86fc19a

🔍 Inspect the deploy log: https://app.netlify.com/sites/jellyfish-defi/deploys/60b6102c0fa20000078df9d4

😎 Browse the preview: https://deploy-preview-301--jellyfish-defi.netlify.app

[codeclimate]

Code Climate has analyzed commit a7b81c3 and detected 0 issues on this pull request.

View more on Code Climate.

[github-actions]

size-limit report 📦

Path	Size	Loading time (3g)	Running time (snapdragon)	Total time
packages/jellyfish/dist/jellyfish.umd.js	19.6 KB (0%)	393 ms (0%)	156 ms (-0.03% 🔽)	549 ms

[codecov]

Codecov Report

Merging #301 (8f2be4b) into main (6554eff) will increase coverage by 0.03%.
The diff coverage is 100.00%.

❗ Current head 8f2be4b differs from pull request most recent head a7b81c3. Consider uploading reports for the commit a7b81c3 to get more accurate results

@@            Coverage Diff             @@
##             main     #301      +/-   ##
==========================================
+ Coverage   97.05%   97.09%   +0.03%     
==========================================
  Files          91       91              
  Lines        2514     2545      +31     
  Branches      319      323       +4     
==========================================
+ Hits         2440     2471      +31     
  Misses         74       74              

Impacted Files	Coverage Δ
...ellyfish-transaction/src/buffer/buffer_composer.ts	99.48% <100.00%> (+0.01%)	⬆️
...ages/jellyfish-transaction/src/script/defi/dftx.ts	97.36% <100.00%> (+0.07%)	⬆️
...jellyfish-transaction/src/script/defi/dftx_pool.ts	100.00% <100.00%> (ø)
...ckages/jellyfish-transaction/src/script/mapping.ts	96.59% <100.00%> (+0.07%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 69e7f9c...a7b81c3. Read the comment docs.

[jingyi2811]

Suraj will be the owner of this PR