[Core] Improve the job detail filling process

[DanielZhangQD]

Improve the job detail filling process to reduce the time spent retrieving the jobs.
The time spent to fill the job details is reduced from 8-11s to less than 1s.

• Remove unnecessary db calls
• Fetch all the cluster to handle map in one db call

Tested (run the relevant ones):

• Code formatting: install pre-commit (auto-check on commit) or bash format.sh
• Any manual or new tests for this PR (please specify below)
  • Test with 5000 managed jobs
    • The API response is the same with that in master
    • The time spent to fill the job details is reduced from 8-11s to less than 1s
• All smoke tests: /smoke-test (CI) or pytest tests/test_smoke.py (local)
• Relevant individual tests: /smoke-test -k test_name (CI) or pytest tests/test_smoke.py::test_name (local)
• Backward compatibility: /quicktest-core (CI) or pytest tests/smoke_tests/test_backward_compat.py (local)

[DanielZhangQD]

/smoke-test --managed-jobs --aws