Use pypika's SqlContext to improve performance

[henadzit]

Description

• Update the code to use pypika's SqlContext introduced in pypika-tortoise 0.5.0

Motivation and Context

This PR improves the performance of SQL generation by pypika (see the Codspeed comment for more details), hence improving over query performance:

• 23% improvement in the test_get_many_fields benchmark
• 9% improvement in the test_filter_many_filters benchmark
• 4% improvement in test_filter_few_fields

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.

[codspeed-hq]

CodSpeed Performance Report

Merging #1837 will improve performances by 23.49%

_{Comparing henadzit:feat/pypika-sql-context (d487ebe) with develop (46e3aef)}

Summary

⚡ 1 improvements
✅ 7 untouched benchmarks

Benchmarks breakdown

	Benchmark	develop	henadzit:feat/pypika-sql-context	Change
⚡	test_get_many_fields	1.4 ms	1.2 ms	+23.49%

[coveralls]

Pull Request Test Coverage Report for Build 12713770244

Details

• 26 of 29 (89.66%) changed or added relevant lines in 8 files are covered.
• No unchanged relevant lines lost coverage.
• Overall first build on feat/pypika-sql-context at 90.252%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
tortoise/backends/mysql/executor.py	2	3	66.67%
tortoise/indexes.py	0	2	0.0%

Totals
Change from base Build 12713629151:	90.3%
Covered Lines:	6432
Relevant Lines:	7011

---

💛 - Coveralls

[henadzit]

@abondar any chance you can have a look at this? Thanks!

[abondar]

Thank you, it looks much better that way, then implicit kwargs

I'll try to not miss when you update PR with actual lib version to reapprove, but if I don't - don't hesitate to tag me please. I am still a little bit in new year vibe (:

[henadzit]

@abondar happy new year!

I've updated pypika-tortoise, so it's ready for review again.