Use canonical dpnp.max/dpnp.min instead of amax/amin aliases in docstrings and internal code

[antonwolfy]

The pointing docstrings and internal usage at the alias pages forces readers to click through a second time to reach the real
max/min documentation; referencing the canonical names directly avoids that indirection.

• Have you provided a meaningful PR description?
• Have you added a test, reproducer or referred to an issue with a reproducer?
• Have you tested your changes locally for CPU and GPU devices?
• Have you made sure that new changes do not introduce compiler warnings?
• Have you checked performance impact of proposed changes?
• Have you added documentation for your changes, if necessary?
• Have you added your changes to the changelog?

[github-actions]

View rendered docs @ https://intelpython.github.io/dpnp/pull/2990/index.html

[coveralls]

coverage: 78.107%. remained the same — replace-amin-amax-in-docs-and-code into master

[github-actions]

Array API standard conformance tests for dpnp=0.21.0dev2=py313h509198e_15 ran successfully.
Passed: 1371
Failed: 4
Skipped: 5