Extend metrics support for Redis cache calls

• Epic: &9313

Proposal

We want to extend metrics support for all Redis cache calls. Metrics were introduced in !96382 (merged), but there are used only for a specific methods.

We can provide labels to existing Rails.cache calls to automatically collect metrics.

# Labels define default settings
Rails.cache.fetch('cache-key', labels: { cache_identifier: 'Class#cache_key', backing_resource: :gitaly }) do
  'do work'
end

Goals

Add an interface that allows to provide feature_category, backing_resource and cache_identifier to each Redis call