Add function-calc-no-invalid rule

[ota-meshi]

Which issue, if any, is this issue related to?

Closes #3820

Is there anything in the PR that needs further explanation?

This PR add function-calc-no-invalid rules.
A new rule that reports an invalid expression of the calc() function.

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I created calc expression parser with reference to parser.jison of postcss-calc.
The main changes from parser.jison of postcss-calc are below.

• Changed to case insensitive.
• Changed to accept an unknown expression.
• Changed to include location in node.
• Added predefined units with stylelint. (e.g. vm)
• Changed the calculation process of minus.
• Changed to integrate length units into LengthValue.

[jeddy3]

Oh wow, this is great!

My original concern was that this rule would not meet the following criteria for inclusion:

• Has a clear and unambiguous finished state.

However, because this rule is using a spec compliant parser, I think it might meet this criteria.

Can anyone think of a reason not to include this rule in core?

[alexander-akait]

Very very good job, need test nested calc

[ota-meshi]

@evilebottnawi Thank you for review!
I added test cases and fixed bugs.

[alexander-akait]

Great job!

I think we should union with postcss-calc and move parser as separate package or include this logic in postcss-value-parser, but don't have time on this right now.

[alexander-akait]

I think we need more tests around scss, less and css-in-js (?) syntaxes (variables, nested function). Example: calc(10px + $var)? Thanks for good job again

[ota-meshi]

I think we should union with postcss-calc and move parser as separate package or include this logic in postcss-value-parser, but don't have time on this right now.

True, let me know if I can help.

I think we need more tests around scss, less and css-in-js (?) syntaxes (variables, nested function). Example: calc(10px + $var)?

I'm not familiar with less and css-in-js, so I will gradually catch up and add test cases.

[alexander-akait]

@ota-meshi let's add some tests with variables $var, @var and functions calc(10px + myFunc()) and we can merge

[ota-meshi]

I added the test cases.
Please tell me if the test cases is not enough.

[jeddy3]

LGTM

@evilebottnawi Any further requests, or does this look good to you now?

[alexander-akait]

Looks good 👍

[jeddy3]

@ota-meshi Thanks for adding this epic new rule!

• Added: function-calc-no-invalid rule (#3833).