feat: include postgrest in monorepo, finalize monorepo switch

[o-santi]

What kind of change does this PR introduce?

Include postgrest-py, the last remaining package to the monorepo switch. Also consolidate docs in README and tooling usage (make help, make clean, etc).

Additional context

• Add it as an entry to the workspace in pyproject.toml
• Copy the relevant files to src/{project_name} (including CHANGELOG.md, LICENSE and Makefile!)
• Use the package directly from workspace in src/supabase, instead of from pypi.
• Add its tests to the main Makefile, and the directory itself to make publish.
• For projects using unasync-cli, switch away from it.
• Add it to release please
• Add it to main README.md

[coveralls]

Pull Request Test Coverage Report for Build 17411465349

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.6%) to 93.74%

---

Totals
Change from base Build 17276837493:	0.6%
Covered Lines:	8610
Relevant Lines:	9185

---

💛 - Coveralls