Merge branch 'modifier-release-fix' of https://github.com/eltang/qmk_firmware into modifier-release-fix

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Update the memory consumption total value in README

Update the memory consumption of PREVENT_STUCK_MODIFIERS in README

Cut the memory consumption of PREVENT_STUCK_MODIFIERS in half

Expose the pressed_actions_cache global variable

Always provide an implementation of process_action_nocache

process_action may be called either with key cache or without it

If one wants to temporarily disable the key cache (for example because
it interferes with a macro), `disable_action_cache` must be set to
`true`. `process_action_nocache` is a simple wrapper doing just that for
a single call.

Document the issue of stuck modifiers