Auto merge of #10524 - mauricioc:keyword_values, r=SimonSapin

Add some Gecko-supported CSS keyword properties

I have added all properties that are marked with (exactly) PARSE_VALUES and H | K in [0] to properties.mako.rs, as part of #10408. A few questions and remarks:

* I created a SVG style struct. Should those properties be somewhere else instead?
* I did not know what to do with ime-mode (which lives in nsStyleUIReset), so I did not include it.
* Servo already has a -servo-overflow-clip-box property, while Gecko has overflow-clip-box. Should those be consolidated?
* There is a code comment (marked with XXX) about scroll-snap-type-y. Should I add a <%self:longhand> template tag for that, similar to the one in overflow-y?

I am getting error E0053 while trying to run "./mach build-geckolib -r" on master, and the bholley/stylo branch doesn't support the products keyword argument yet, so I haven't exactly checked this compiles properly. It doesn't add any new compilation errors before the E0053 one, though.

Let me know if some extra information (say, a table saying where each property went) would be useful in the review process. r? @bholley

[0] https://docs.google.com/spreadsheets/d/1pSw2SjNxXZAQ19SAuNKcs5u4S7Zkc1ebEOkSP4oITUQ/edit?pref=2&pli=1

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="35" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/10524)
<!-- Reviewable:end -->

0 files changed, 0 insertions, 0 deletions