Changes Vega class name to match source code

[JasonWeill]

References

Fixes #12377

Code changes

Changes CSS class name in source code.

User-facing changes

Screen shot before changing the style sheet

Screen shot after changing the style sheet

Note that Firefox disregards the margin-left and margin-right rules because it doesn't apply them to elements with style display: table-cell, like this one.

Backwards-incompatible changes

None.

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[fcollonval]

LGTM

[fcollonval]

@meeseeksdev please backport to 3.3.x

[github-actions]

Benchmark report

The execution time (in milliseconds) are grouped by test file, test type and browser.
For each case, the following values are computed: min <- [1st quartile - median - 3rd quartile] -> max.

The mean relative comparison is computed with 95% confidence.

Results table

Test file	large_code_notebook	large_md_notebook
open
chromium
actual	4470 <- [4593 - 4679 - 4751] -> 5056	3082 <- [3237 - 3288 - 3347] -> 3498
expected	4403 <- [4547 - 4626 - 4702] -> 5064	3138 <- [3241 - 3312 - 3370] -> 3521
Mean relative change	0.9% ± 0.7%	-0.6% ± 0.7%
switch-from
chromium
actual	762 <- [821 - 841 - 859] -> 1104	527 <- [554 - 570 - 584] -> 1194
expected	756 <- [812 - 838 - 860] -> 1071	524 <- [557 - 571 - 585] -> 1216
Mean relative change	0.9% ± 1.6%	1.1% ± 4.6%
switch-to
chromium
actual	382 <- [450 - 462 - 474] -> 597	293 <- [331 - 341 - 353] -> 389
expected	378 <- [446 - 459 - 469] -> 530	291 <- [330 - 340 - 351] -> 382
Mean relative change	0.7% ± 1.7%	0.9% ± 1.5%
close
chromium
actual	645 <- [1133 - 1155 - 1177] -> 1309	536 <- [566 - 579 - 594] -> 651
expected	635 <- [1128 - 1147 - 1172] -> 1244	540 <- [567 - 579 - 592] -> 622
Mean relative change	0.1% ± 3.7%	0.3% ± 0.9%

Changes are computed with expected as reference.