[PP-1] Add a persistent cache for plugin attribute parsing

Problem/Motivation

Postponed on #3486503: Add a persistent cache for file-based discovery based on FileCache.

We can use the same logic being added there for YAML files, to cache the results of attribute parsing. The current cache is in apcu which can't be shared between the cli and web requests, or between different web heads, and also doesn't handle large amounts of data particularly well.

This should be both a cpu and memory improvement on what would otherwise be cold cache requests due to the higher hit cache hit rates.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

Introduced terminology

API changes

Data model changes

Release notes snippet