docs: test_kdoc_parser: add support for dynamic test creation

docs: test_kdoc_parser: add support for dynamic test creation

Use the content of kdoc-test.yaml to generate unittests to
verify that kernel-doc internal methods are parsing C code
and generating output the expected way.

Depending on what is written at the parser file at
kdoc-test.yaml, up to 5 tests can be generated from a single
test entry inside the YAML file:

1. from source to kdoc_item: test KernelDoc class;
2. from kdoc_item to man: test ManOutput class;
3. from kdoc_item to rst: test RestOutput class;
4. from source to man without checking expected KdocItem;
5. from source to rst without checking expected KdocItem.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <7ec2593c5b19de3e3b1d8de92675f6b751d3fa21.1773823995.git.mchehab+huawei@kernel.org>