Gallery: Dynamic variation has confusing "Convert to ..." actions #80613

Related #78796.

The convertToStatic event action has two labels - "Convert to individual images" and "Convert to images," and both have a similar problem, IMO. This came up in a Twitter conversation, and I totally misunderstood what button was doing.

• Intent in the Gallery block context can be easily misunderstood. My expectation was that the action would unwrap the Gallery into individual Image blocks, but it changes the variation.
• Actions are too prominent. Since we're already working with variations. Maybe we should just convert the existing UIs. Related Fine-tune the GIF → video conversion feature (follow-up to #78410) #79787.

P.S. History also seems broken after conversion, not really related here, but can be fixed with refactoring. Fixed in #80665

Screencast