Support yapf ignore configuration in pyproject.toml

[dclong]

Now that yapf supports formatting configuration in pyproject.toml, it's appealing to support yapf ignore configuration in pyproject.toml too so that we can configure everything about yapf in pyproject.tom.

[dclong]

@hirosassa
The PR #937 addresses this issue. However, it uses a triple quotes string to specify multiple patterns. It is more nature to allow users to specify a list of patterns. Anyway, the code tries to parse the triple quotes string to a list of patterns. Basically, in addition to the following configuration style,

[tool.yapfignore]
ignore_patterns="""
temp/**/*.py
temp2/*.py
"""

allowing the below configuration style as well.

[tool.yapfignore]
ignore_patterns = [
    "temp/**/*.py",
    "temp2/*.py"
]

[bwendling]

PR #937 uses the toml module to do the parsing. Does that not have support for a list of patterns?

[hirosassa]

Thanks for your suggestion. I'll try it.

[hirosassa]

@dclong Fixed the issue in #946

@gwelymernans thanks for merging the PR!