Implement `last` for querysets and models

[ruitcatarino]

Description

This implements the last (https://docs.djangoproject.com/en/5.1/ref/models/querysets/#last methods similar to Django.

Motivation and Context

Like I explained in the issue https://github.com/tortoise/tortoise-orm/issues/1753 I miss this method as someone coming from Django.

How Has This Been Tested?

Well I implemented tests to validate the usage of this method and ran them with make test. I also did some local testing.

Checklist:

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

The existing tests are not passing in the develop branch for me. But the new created tests are passing. I'll post the output of my tests here

==================================================================================================== short test summary info ====================================================================================================
FAILED tests/test_queryset.py::TestQueryset::test_delete_limit - tortoise.exceptions.OperationalError: near "LIMIT": syntax error
FAILED tests/test_queryset.py::TestQueryset::test_delete_limit_order_by - tortoise.exceptions.OperationalError: near "ORDER": syntax error
FAILED tests/test_queryset.py::TestQueryset::test_delete - tortoise.exceptions.OperationalError: near "ORDER": syntax error
FAILED tests/test_update.py::TestUpdate::test_update_with_limit_ordering - tortoise.exceptions.OperationalError: near "ORDER": syntax error
ERROR tests/test_default.py
ERROR tests/test_two_databases.py
4 failed, 1156 passed, 67 skipped, 4 xfailed, 20 warnings, 2 errors in 69.54s (0:01:09)

[coveralls]

Pull Request Test Coverage Report for Build 11646693216

Details

• 13 of 14 (92.86%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.005%) to 89.074%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
tortoise/queryset.py	10	11	90.91%
<!--	Total:	13	14	92.86%	-->

Totals
Change from base Build 11641255981:	0.005%
Covered Lines:	6025
Relevant Lines:	6650

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💛 - Coveralls