relates to #20225

This is a tracking issue for the Post Demo / Origin trial feedback for amp-experiment 1.0 😄

• Split up this tracking issue 😂
• Interfaces for MutationRecord Types (should have a validate() and mutate())
• Better Style Attribute Restrictions
• Enforce Limitations
• Implement Schedule
• Implement Re-ordering
• If attribute validation not moved to cache, separate style property and value validation.
• Feedback: VARIANT returns 'none' for inactive experiments and '' for invalid/unknown experiments. This is weird, expected to be tracked as 'none' since '' is falsy
• Transitions on elements can affect how styles get applied. E.g Having a 1 second transition on height, can cause an element to change over time and change how things are rendered while reading article.
• Empty mutation experiments are very common. Can/Should we support them in the future?
• Most AMP Components cannot be mutated, as they read their attributes and things on buildCallback(), or before layout usually. Thus, templating them would probably be best if possible.
• Allow disabling and specifying an experiment