[Feature] Support NIQE

[Z-Fran]

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Motivation

Support NIQE metrics for low-level vision tasks.

Modification

Support NIQE metric.

Implementation in MMEditing-1.x and Performance Comparison

MMEditing PR: open-mmlab/mmagic#1608

BC-breaking (Optional)

Does the modification introduce changes that break the backward-compatibility of the downstream repos?
If so, please describe how it breaks the compatibility and how the downstream projects should modify their code to keep compatibility with this PR.

Use cases (Optional)

If this PR introduces a new feature, it is better to list some use cases here, and update the documentation.

Checklist

1. Pre-commit or other linting tools are used to fix the potential lint issues.
2. The modification is covered by complete unit tests. If not, please add more unit test to ensure the correctness.
3. If the modification has potential influence on downstream projects, this PR should be tested with downstream projects, like MMDet or MMCls.
4. The documentation has been modified accordingly, like docstring or example tutorials.

[CLAassistant]

All committers have signed the CLA.

[C1rN09]

Generally good! Please modify api documents && support_matrix documents accordingly.

[C1rN09]

Also please update api docs

[C1rN09]

LGTM with 2 comments:

1. support_matrix.md should not be updated, because it will lead to conflicts. We will update it later.
2. also add zh_cn api docs 😄