feat: [SFCC-517][SEO-friedly URLs] Added stateToRoute and routeToState custom mapping

[ede-somogyi-algolia]

Replace InstantSearch's default routing: true (the built-in simple state mapping plus the default history router) in the SFRA instantsearch-config.js with a custom router and stateMapping. The storefront query string on category and search results pages becomes short and stable - for example ?q=jacket&brand=Apple&size=M&sort=price-asc&page=2 - instead of the index-prefixed, bracketed default.

This PR covers the URL routing (state/route mapping) only. The rel="canonical" work is handled separately.

The mapping is a sample covering the facets the cartridge ships with. Clients who add their own facet attributes extend the two functions.

Before / after

Category landing page, size L selected (master-level record model):

Before (default simple mapping + default router):

.../s/RefArch/womens/clothing/tops/?zzgk_006_dx__RefArch__products__en_US[refinementList][variants.size][0]=L

After:

.../s/RefArch/womens/clothing/tops/?size=L

Pre-existing parameters in the URL are kept intact.

[codacy-production]

Not up to standards ⛔

🔴 Issues 12 high

Alerts:

⚠ 12 issues (≤ 0 issues of at least high severity)

Results:
12 new issues

Category	Results
Security	12 high

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🟢 Metrics 0 duplication

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Duplication	0

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_{TIP This summary will be updated as you push new changes.}

[sbellone]

Looks good, there is mostly just an issue with the overridden query string.

[sbellone]

Works well 👍