chore(hubble): Enhance code style in hubble

[returnToInnocence]

Purpose of the PR

• subtask of [Enhancement] Unify & clean code style in hubble & client #591

Main Changes

Verifying these changes

• Trivial rework / code cleanup without any test coverage. (No Need)
• Already covered by existing tests, such as (please modify tests here).
• Need tests and can be verified as follows:
  • Check against the HugeGraph Code Style Guide

Does this PR potentially affect the following parts?

• Nope
• Dependencies (add/update license info)
• Modify configurations
• The public API
• Other affects (typed here)

Documentation Status

• Doc - TODO
• Doc - Done
• Doc - No Need

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 62.41%. Comparing base (b066b80) to head (110cd1e).
Report is 27 commits behind head on master.

❗ Current head 110cd1e differs from pull request most recent head 7bf19b2. Consider uploading reports for the commit 7bf19b2 to get more accurate results

Additional details and impacted files

@@             Coverage Diff              @@
##             master     #592      +/-   ##
============================================
- Coverage     62.49%   62.41%   -0.08%     
- Complexity     1903     1931      +28     
============================================
  Files           262      267       +5     
  Lines          9541     9739     +198     
  Branches        886      891       +5     
============================================
+ Hits           5963     6079     +116     
- Misses         3190     3267      +77     
- Partials        388      393       +5     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[imbajin]

Thanks~