feat(tracking): impression tracking for home sections

[nickskalkin]

The type of this PR is: Feat

This PR solves ONYX-1859

Description

Adds Cohesion RailViewed impression events for every section on the home feed (plus MyBids). An event fires once per mount after the rail stays sufficiently visible for ~1 second, so we capture genuine impressions instead of scroll-by glances.

Update: opened #17206 for item impressions tracking (builds on top of the current PR)

[relativeci]

#8471 Bundle Size — 8.93MiB (+0.1%).

2c01024(current) vs 0a7c789 main#8468(baseline)

Warning

Bundle contains 29 duplicate packages – View duplicate packages

Bundle metrics   4 changes 2 regressions

	Current #8471	Baseline #8468
Initial JS	2.89MiB(~+0.01%)	2.89MiB
Initial CSS	0B	0B
Cache Invalidation	97.44%	97.44%
Chunks	111	111
Assets	114	114
Modules	5619(+0.16%)	5610
Duplicate Modules	659(+0.46%)	656
Duplicate Code	4.99%(+0.2%)	4.98%
Packages	248	248
Duplicate Packages	28	28

Bundle size by type   1 change 1 regression

	Current #8471	Baseline #8468
JS	8.7MiB (+0.11%)	8.69MiB
Other	234.14KiB	234.14KiB

Bundle analysis report Branch nickskalkin/home-page-rail-impre... Project dashboard

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