Add ranges for warnings

[adalinesimonian]

Partially addresses #5694

Adds range support for warnings.

Tasks:

• Update PostCSS to 8.4
• Update postcss-value-parser to 4.2
• Update Warning type
• Update Problem type
• Update report function
• Update some rules
• Update tests for these rules

[adalinesimonian]

What this generally looks like in VS Code with the appropriate changes downstream:

[jeddy3]

You're doing amazing work extending the capabilities of both PostCSS and Stylelint with this range stuff!

[jeddy3]

(Removed the label to be consistent with our usage, i.e. only pr: * labels for pull requests.)

[adalinesimonian]

I was running into issues trying to determine the end position for functions and other nodes provided by postcss-value-parser. I've opened up a PR there that will resolve this problem: TrySound/postcss-value-parser#83

[ybiquitous]

I've removed the unused utility functions below:

• getWhitespaceStartIndex() 2c59689
• getWhitespaceEndIndex() 9c675ce
• getWordStartIndex() acca7dd
• getWordEndIndex() 2755c1b

Let's add them again if they are necessary.

[ybiquitous]

All the rules have not been supported yet, but this pull request is ready to review. 🎉
(we need to address the remaining rules on other pull requests.)

[jeddy3]

@ybiquitous Thank you so much for picking this up! You've done fantastic work on top of @adalinesimonian's.

All the code LGTM. Let's update our docs too. I think we have a couple of examples that need updating here, here and here.

I think once that's done we can merge and release.

All the rules have not been supported yet, but this pull request is ready to review.

I agree. When it comes to the other rules, I don't think we need to add end positions for all the reject tests. We should add just enough of them to be confident that the extra endIndex logic is working.

[ybiquitous]

Ah, thanks for suggesting updating the docs. I'll do it soon. 👍🏼

[ybiquitous]

Updating the docs was done via 13030a9.

[jeddy3]

Fantastic work, thank you!

LGTM.

Feel free to merge. Any idea for the changelog entry? Perhaps:

• Added: ranges for warnings that can be used by formatters and integrations

[ybiquitous]

@jeddy3 Thanks for the review and suggestion! I'll do it.

[ybiquitous]

Done.

• Added: ranges for warnings that can be used by formatters and integrations (#5725).