Make tree search match the package path of the test result (fixes #1077)

[zocek]

Context

Searching on the Packages tab cannot find tests by their package path (fixes #1077).

Two things break it today:

1. The tree text filter only matches the displayed node name. In the Packages tab the group names are dot-collapsed package segments (e.g. io.qameta.allure → PullRequestsWebTest), so a query that spans segment boundaries (e.g. allure.PullRequestsWebTest or a full package path) matches no node name at all.
2. Even when a query does match a group name, the bottom-up tree projection has already dropped all of the group's non-matching leaves, and the resulting empty group is then hidden by the status filter (byStatuses requires children.length > 0) — so the user ends up with no results whatsoever.

This change computes a searchPath for every tree node during normalization (normalizeNodes) — the dot-joined names of the node's ancestors plus its own name — and lets the tree text filter (byText) match it. A query for a package, a class, or any dotted-path substring now matches the leaves themselves, so the package is shown together with its tests. The fix is frontend-only and works for every data source, since the path is derived from the tree structure itself. The display is unchanged — searchPath is only consulted by the search.

Since byText is shared tree plumbing, searching a group name on the Suites/Behaviors/Categories tabs now also reveals the tests inside that group instead of showing nothing, which matches the expectation described in the issue.

Tests: Playwright e2e cases in tree.shared.spec.mts — searching across collapsed package segments and by root package on the Packages tab, and searching a suite (class) name on the Suites tab. All three assertions fail without this fix.

Checklist

• Sign Allure CLA
• Provide unit tests