Show other snappable lines during grid ruler resize

[ruggi]

Problem:

During grid ruler resize the other "snappable" lines for the axis should be shown on the grid instead of the full grid placeholders.

Fix:

This PR extends the previous snapline code to include lines for the other columns/rows in the current axis, because the regular placeholders would show too much information.

As a future extension it would make sense to show the lines in between any gap that may have been defined on the axis.

Before	After

Manual Tests:
I hereby swear that:

• I opened a hydrogen project and it loaded
• I could navigate to various routes in Play mode

Fixes #6721

[github-actions]

Try me

[relativeci]

#15422 Bundle Size — 58.22MiB (~+0.01%).

3f79745(current) vs d1d46c1 master#15416(baseline)

Warning

Bundle contains 70 duplicate packages – View duplicate packages

Bundle metrics   2 changes 1 regression

	Current #15422	Baseline #15416
Initial JS	41.19MiB(~+0.01%)	41.19MiB
Initial CSS	0B	0B
Cache Invalidation	18.25%	18.12%
Chunks	20	20
Assets	22	22
Modules	4190	4190
Duplicate Modules	213	213
Duplicate Code	27.24%	27.24%
Packages	477	477
Duplicate Packages	70	70

Bundle size by type   2 changes 1 regression 1 improvement

	Current #15422	Baseline #15416
JS	58.21MiB (~+0.01%)	58.21MiB
HTML	9.4KiB (-0.21%)	9.42KiB

Bundle analysis report Branch feat/other-snap-lines-during-gri... Project dashboard

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