Fix executor todos

[waketzheng]

Description

Fix all TODOs in tortoise/backend/base/executor.py

Motivation and Context

How Has This Been Tested?

make ci

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added the changelog accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[coveralls]

Pull Request Test Coverage Report for Build 9741475399

Details

• 26 of 28 (92.86%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.05%) to 89.048%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
tortoise/backends/base/executor.py	26	28	92.86%

Totals
Change from base Build 9646263030:	-0.05%
Covered Lines:	5922
Relevant Lines:	6549

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 10154861691

Details

• 26 of 28 (92.86%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.05%) to 89.112%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
tortoise/backends/base/executor.py	26	28	92.86%

Totals
Change from base Build 10115140001:	-0.05%
Covered Lines:	5955
Relevant Lines:	6568

---

💛 - Coveralls