Bug 1567380 [wpt PR 17923] - Add toast type attribute support with ID…

…L property and default styles, a=testonly

Automatic update from web-platform-tests
Add toast type attribute support with IDL property and default styles

This change adds the toast type attribute and property
according to the PR on the toast explainer here:
jackbsteinberg/std-toast#49

There is still work TODO on implementing this PR,
w.r.t the showToast type option, a11y behavior for warning / error,
and default features for those types (Infinity duration, closebutton, etc)

Additionally, a follow-up CL will come out to reconfigure the current
reflection tests for type and open to use established reflection test
methodology
(ex: https://cs.chromium.org/chromium/src/third_party/blink/web_tests/wpt_internal/std-switch/tentative/form-associated-basic.js)

Bug: 972945
Change-Id: I58c7079dc4f748928eea44103dece835e549986e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1708313
Commit-Queue: Jack Steinberg <jacksteinbergchromium.org>
Reviewed-by: Fergal Daly <fergalchromium.org>
Cr-Commit-Position: refs/heads/master{#680073}

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wpt-commits: 109a7d171d08bceb61dce865576de3c15f61c16c
wpt-pr: 17923

UltraBlame original commit: 6b977ac34f96effce492d7b372f3cb8f9fe3b3b5