Add smoke tests to library and application

[joerideg]

Add unit / integration tests for some of the library components / services:
brx-spartacus-lib/src/lib/components/pathways-recommendations/pathways-recommendations.component.ts
brx-spartacus-lib/src/lib/components/spartacus-banner/spartacus-banner.component.ts
brx-spartacus-lib/src/lib/components/spartacus-product-list/spartacus-product-list.component.ts
brx-spartacus-lib/src/lib/services/brx-endpoint.service.ts
brx-spartacus-lib/src/lib/services/brx-pathways-recommendations.service.ts
brx-spartacus-lib/src/lib/spartacus/brx/adapters/brx-product-search-adapter.ts
brx-spartacus-lib/src/lib/spartacus/brx/normalizers/brx-product-normalizer.ts
brx-spartacus-lib/src/lib/spartacus/brx/normalizers/brx-product-search-normalizer.ts

Add integration test with mocked backend data snap shot test a few routes: 
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