Add static caching to BreadcrumbManager::build()

Problem/Motivation

When profiling a site, I noticed that schema_metatag's breadcrumb manager causes breadcrumbs to be fetched a second time - running all the breadcrumb services' build() methods twice. Because breadcrumbs are generally per-page, this is a lot of additional work across a site.

It's not really possible to cache this in schema_metatag, or not unless it decorated core's breadcrumb service. Since other metatag-ish modules might do the same thing, I think we should add a static cache to core so that breadcrumb building can only ever happen once.

https://git.drupalcode.org/project/schema_metatag/-/blob/3.1.x/src/Plugi...

Should probably use the cache.memory bin.

Steps to reproduce

1. Place the System Breadcrumb block in a region that is rendered on taxonomy term pages.
2. Add code to call \Drupal::service('breadcrumb')->build() for the current route during page rendering, following the approach used by schema_metatag's BreadcrumbList implementation.
3. Implement hook_system_breadcrumb_alter() to log each invocation for debugging purposes.
4. Load the taxonomy term page once as an anonymous user and compare the logs. Two breadcrumb builds are recorded on the main branch, while only one is recorded with the merge request applied.

Proposed resolution

BreadcrumbManager::build() stores the generated breadcrumb in the cache.memory bin. The cache ID consists of the route name and a hash of the raw route parameters. Each cache entry holds a WeakReference to the request for which the breadcrumb was built, ensuring that cached breadcrumbs are reused only within the same request. Cache entries use the breadcrumb's cache tags for invalidation.

Remaining tasks

User interface changes

Introduced terminology

API changes

Data model changes

Release notes snippet